IPAC2015 - List of Keywords (synchrotron)

Paper	Title	Other Keywords	Page
MOBB1	Status of the Proton Beam Commissioning at the MedAustron Ion Beam Therapy Centre	injection, proton, acceleration, extraction	28
	A. Garonna, M. Kronberger, T.K.D. Kulenkampff, C. Kurfürst, F. Osmić, L.C. Penescu, M.T.F. Pivi, C. Schmitzer, P. Urschütz, A. Wastl EBG MedAustron, Wr. Neustadt, Austria
	The MedAustron accelerator, located in Wiener Neustadt (Austria), will deliver clinical beams of protons (60-250 MeV) and carbon ions (120-400 MeV/n) to three ion beam therapy irradiation rooms (IR). Clinical beams and proton beams up to 800 MeV will be provided in a fourth IR, dedicated to non-clinical research. A slow-extracted proton beam of maximum clinical energy has been delivered for the first time in IR3 in October 2014, thus providing the technical proof-of-principle of the accelerator chain. The recent related beam commissioning efforts included setting up of the multi-turn injection into the synchrotron at 7 MeV, the acceleration on first harmonic up to 250 MeV, the slow extraction on the third integer resonance with a betatron core and the matching of the High Energy Beam Transfer line. The accelerator optimization phase leading to IR3 medical commissioning of proton beams is ongoing. The main characteristics of the MedAustron accelerator system will be presented, along with the results obtained during the commissioning process.
	Slides MOBB1 [6.596 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOBB1
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MOBC2	High-Performance Simulations of Coherent Synchrotron Radiation on Multicore GPU and CPU Platforms	GPU, simulation, electron, radiation	42
	B. Terzić, A.L. Godunov ODU, Norfolk, Virginia, USA A. Arumugam, D. Ranjan, M. Zubair ODU CS, Norfolk, Virginia, USA
	Coherent synchrotron radiation (CSR) is an effect of self-interaction of an electron bunch as it traverses a curved path. It can cause a significant emittance degradation and microbunching. We present a new high-performance 2D, particle-in-cell code which uses massively parallel multicore GPU/GPU platforms to alleviate computational bottlenecks. The code formulates the CSR problem from first principles by using the retarded scalar and vector potentials to compute the self-interaction fields. The speedup due to the parallel implementation on GPU/CPU platforms exceeds three orders of magnitude, thereby bringing a previously intractable problem within reach. The accuracy of the code is verified against analytic 1D solutions (rigid bunch).
	Slides MOBC2 [4.866 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOBC2
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MOAD3	Relative Alignment Within the MAX IV 3 GeV Storage Ring Magnet Blocks	alignment, storage-ring, magnet-design, quadrupole	57
	J.H. Björklund Svensson, M.A.G. Johansson MAX-lab, Lund, Sweden
	Unlike the discrete magnet scheme of previous 3rd generation light sources, the magnet elements of the MAX IV storage rings are integrated in precision-machined magnet blocks. By analyzing the rotating coil measurements made by the magnet suppliers, we determined the relative alignment between consecutive magnet elements, which was found to be <10 microns RMS for all magnet block types in both horizontal and vertical direction. This article presents our analysis and results for the full magnet production series.
	Slides MOAD3 [1.825 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOAD3
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MOPWA011	The Damping of Transverse Coherent Instabilities by Harmonic Cavities	betatron, simulation, damping, electron	102
	F.J. Cullinan, R. Nagaoka SOLEIL, Gif-sur-Yvette, France G. Skripka, P.F. Tavares MAX-lab, Lund, Sweden
	At nonzero chromaticity, the threshold current due to transverse coupled bunch instabilities in an electron storage ring is defined by intrabunch head-tail motion of higher than zeroth order. Multibunch tracking simulations predict that this threshold can be increased to several times its original value through the introduction of bunch lengthening harmonic cavities. One previously suggested explanation is the narrower spectra of the elongated bunches but reliable estimates for the threshold currents are not obtainable for anything other than rigid beam motion since the usual Sacherer formulism is not directly applicable to beams in a non-harmonic potential. A new scheme has been developed in which the decay time of a higher than zeroth order transverse head-tail mode may be estimated by taking into account the synchrotron tune spread generated by the harmonic cavity potential. This scheme is presented along with the results of numerical simulations performed in order to confirm the analytical predictions and justify the assumptions made. The extension of the scheme to more complex scenarios is also discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA011
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MOPWA013	Modeling and Measurements of Spin Depolarization	kicker, electron, resonance, polarization	109
	N. Carmignani, F. Ewald, L. Farvacque, B. Nash, P. Raimondi ESRF, Grenoble, France
	An electron bunch in a storage ring becomes spin polarized due to the Sokolov-Ternov effect. The beam may then be depolarized by applying a horizontal magnetic field oscillating in resonance with the spin tune. This technique has been used to measure the electron energy at numerous synchrotrons. In this paper, we report on modeling and measurements of the polarization and depolarization process at the ESRF. We report the results of a Matlab based parallelized spin tracking code that we developed for these studies. We show the change in depolarization resulting as different physical effects are added to the model.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA013
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MOPWA020	Longitudinal Stability Of Short Bunches in Storage Rings with Strong Longitudinal Focusing	impedance, dipole, simulation, resonance	135
	P. Kuske HZB, Berlin, Germany
	Funding: work supported by the BMBF In the BESSY VSR project, the variable bunch length storage ring, two high gradient accelerating structures at 1.5 and 1.75 GHz will be phased such that long and short bunches can be stored simultaneously. The longitudinal stability of the short bunches is investigated taking into account the shielded CSR- and a purely inductive impedance. Multi particle tracking studies and numerical solutions of the Vlasov-Fokker-Planck equation show that threshold currents for short bunches do not follow the simple scaling law which was found for long bunches. The inductive impedance can even lower the thresholds for the instability. With an 80 times increased accelerating gradient and reasonable assumptions on the inductive impedance for shorter bunches stable operation can be expected with bunches 1.8 ps long (RMS-value) and 0.8 mA current. According to the calculations and operating in a dedicated low-α mode will produce stable 40 μA bunches with 400 fs length
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA020
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MOPWA022	Influence of Transient Beam Loading on the Longitudinal Beam Dynamics at BESSY VSR	beam-loading, damping, simulation, cavity	141
	M. Ruprecht, P. Goslawski, A. Jankowiak, A. Neumann, M. Ries, G. Wüstefeld HZB, Berlin, Germany T. Weis DELTA, Dortmund, Germany
	BESSY VSR, a scheme where 1.7 ps and 15 ps long bunches (rms) can be stored simultaneously in the BESSY II storage ring has recently been proposed . The strong longitudinal bunch focusing is achieved by superconducting high gradient RF cavities. If the bunch fill pattern exhibits a significant inhomogeneity, e.g. due to gaps, transient beam loading causes a distortion of the longitudinal phase space which is different for each bunch. The result are variations along the fill pattern in synchronous phase, synchrotron frequency and bunch shape. This paper presents investigations of transient beam loading and depicts the consequences on bunch length, phase stability and longitudinal multi-bunch oscillations for the projected setup of BESSY VSR. G. Wüstefeld, A. Jankowiak, J. Knobloch, M. Ries, Simultaneous Long and Short Electron Bunches in the BESSY II Storage Ring, Proceedings of IPAC2011, San Sebastián, Spain
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA022
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MOPWA023	Preserving Information of the Three Spatial Electron Beam Dimensions in One Streak Camera Measurement	operation, electron, photon, diagnostics	144
	M.T. Switka, W. Hillert ELSA, Bonn, Germany
	Funding: Work funded by the DFG within SFB/TRR16 At the pulse stretcher ring ELSA, a streak camera is used for the analysis of visible synchrotron radiation. It functions as fast time resolving beam diagnostic apparatus capable of visualizing dynamics down to the picosecond time range. The optical beamline splits the photon beam and projects the electron beam's image onto the streak camera with transversely perpendicular orientation and slight displacement, thereby providing simultaneous imaging of both transverse planes. Thus, the information of bunch and beam dynamics in three dimensions is preserved and can be observed in slow sweep or synchroscan operation. Characteristics and exemplary measurements, demonstrating the capabilities and limits of this technique, are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA023
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MOPWA024	Estimation of the Ion Density in Accelerators using the Beam Transfer Function Technique	ion, electron, betatron, impedance	147
	D. Sauerland, W. Hillert ELSA, Bonn, Germany A. Meseck HZB, Berlin, Germany
	Funding: Funded by the federal ministry of education and science of Germany The ELSA stretcher ring of Bonn University serves external hadron physics experiments with a quasi continuous electron beam of up to 3.2 GeV energy. Ions, being generated by collisions of the circulating electrons with the residual gas molecules, accumulate inside the beam potential, causing incoherent tune shifts and coherent beam instabilities. Detailed measurements were carried out in which ion dynamics is studied in dependence of beam energy and current, filling patterns and bias voltages of the ion clearing electrodes. By measuring the beam transfer function using a broadband transversal kicker, we were able to derive an estimate of the average ion density from the shift and broadening of the tune peak. In this contribution first results of these measurements are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA024
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MOPWA025	Simulation of Laser Cooling of Heavy Ion Beams at High Intensities	laser, ion, scattering, simulation	150
	L. Eidam, O. Boine-Frankenheim, D.F.A. Winters GSI, Darmstadt, Germany
	In the past the principle of Doppler laser cooling was investigated and verified in storage rings in the low energy regime. Within the FAIR project the laser cooling will be applied to high intensity and high energy beams for the first time. The laser cooling results in a further increase of the longitudinal phase space density and in non-Gaussian longitudinal beam profiles. In order to ensure stable operation and optimize the cooling process the interplay of the laser force and high intensity effects has to be studied numerically. This contribution will identify constrains of the cooling scheme for an efficient reduction of momentum spread. For high beam energies the scattering of photons has to be treated stochastically instead of using averaged forces. The modeling of the laser force in a particle in cell tracking code will be discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA025
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MOPWA026	Demonstration of Flat Ion Beam Creation and Injection into a Synchrotron	emittance, solenoid, injection, ion	153
	L. Groening, S. Appel, L.H.J. Bozyk, Y. El Hayek, M.T. Maier, C. Xiao GSI, Darmstadt, Germany
	At GSI an ion beam with different horizontal and vertical emittances has been created from a beam with initially equal emittances. This round-to-flat adoption has been accomplished without any beam loss. In the set-up the beam passes through a stripping foil placed inside a solenoid followed by a skewed quadrupole triplet. The amount of beam flatness has been controlled by setting the solenoid field strength only. Increase of the product of the two transverse emittances is purely due to the stripping process that occurs anyway along an ion linac. Beams with different amounts of flatness were injected into a synchrotron applying horizontal multi-turn injection. The efficiency of injection increased as smaller as the horizontal emittance was set by the round-to-flat adaptor.
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MOPWA034	Coupled-Bunch Instability Suppression Using RF Phase Modulation at the DELTA Storage Ring	damping, storage-ring, electron, feedback	179
	M. Sommer, M. Höner, B.D. Isbarn, S. Khan, B. Riemann, T. Weis DELTA, Dortmund, Germany
	Funding: Work supported by the BMBF under contract no. 05K13PEB The upcoming upgrade of BESSY II, called BESSY-VSR, involves the utilization of superconducting multicell RF-resonators with high accelerating gradients to provide short and long bunches in an electron storage ring simultaneously. Even under the assumption of strongest available damping of beam induced modes, the residual impedances of the cavities may cause collective multibunch instabilities at the frontier of stability available from current bunch-by-bunch feedback systems. At the DELTA electron storage ring, a phase modulation of the driving RF is used to suppress coupled-bunch instabilities and to increase the lifetime. The time dependent frequency variation in the order of the synchrotron frequency gives rise to additional damping of the bunch oscillators by decoherence and Landau damping. The behaviour and the additional damping of the bunch oscillators is investigated by the existing bunch-by-bunch feedback system e.g. the increase of the overall damping might support the capability of feedback systems under extreme operating conditions of BESSY-VSR. G. Wüstefeld et al., Proc. of IPAC'11, San Sebastián, THPC014
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MOPWA039	Emittance Reduction Possibilities in the PETRA III Magnet Lattice	optics, emittance, sextupole, lattice	197
	N. Golubeva, V. Balandin, W. Decking, R. Wanzenberg DESY, Hamburg, Germany
	PETRA III is a third generation light source that has been operated as a user facility since 2010 at DESY. An upgrade for additional beam lines has been carried out, and the recommissioning of the new beam lines is starting in spring 2015. In order to fully exploit the potential of the existing magnet lattice of the PETRA III ring, we present a study of beam optics modifications enabling the reduction of the horizontal emittance without changes of the lattice.
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MOPWA041	Investigation of Radiation Damage of Insertion Devices at PETRA III due to Particle Losses using Tracking Results with SixTrack	radiation, undulator, insertion, insertion-device	203
	G.K. Sahoo, M. Bieler, J. Keil, A. Kling, G. Kube, M. Tischer, R. Wanzenberg DESY, Hamburg, Germany
	PETRA-III is a 3rd generation synchrotron light source dedicated to users at 14 beam lines with 30 instruments since 2009. This operates in 40, 60, 480 or 960 bunches with 100 mA at an electron beam energy of 6 GeV. The horizontal beam emittance is 1nmrad while a coupling of 1% amounts to a vertical emittance of 10 pm-rad. The low emittance is achieved by deploying 80m of damping wigglers in two sections in west and north. Some of these undulators and wiggler devices have accumulated total radiation doses of about 100 kGy. Visible corrosion at the magnet structures of some permanent magnet undulators is seen. High dose rate measured regularly by Thermo Luminescent Dosimeters (TLDs) are monitored, which lead to inspect the magnetic field of all insertion devices in the PETRA tunnel. We are investigating particle losses with tracking simulation using SixTrack to gain a certain understanding of the radiation damage of the insertion devices. The goal is to develop a strategy to safeguard the insertion devices from further radiation damage.
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MOPWA055	Study of Emittance Growth Caused by Space Charge and Lattice Induced Resonances	resonance, space-charge, lattice, emittance	245
	K. Ohmi KEK, Ibaraki, Japan
	Resonance strength and resonance width induced by space charge and lattice nonlinearity is discussed with integrals along a ring like the radiation integrals. Emittance growth is evaluated by model with the resonance width to understand the mechanism. The results are compared with fully PIC simulations.
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MOPWA059	Dynamic Aperture Studies for the FCC-ee	lattice, sextupole, collider, radiation	258
	L.E. Medina Medrano DCI-UG, León, Mexico R. Martin, R. Tomás, F. Zimmermann CERN, Geneva, Switzerland R. Martin Humboldt University Berlin, Berlin, Germany
	Funding: Work supported by the Beam Project (CONACYT, Mexico). Dynamic aperture (DA) studies have been conducted on the latest Future Circular Collider - ee (FCC-ee) lattices as a function of momentum deviation. Two different schemes for the interaction region are used, which are connected to the main arcs: the crab waist approach, developed by BINP, and an update to the CERN design where the use of crab cavities is envisioned. The results presented show an improvement in the performance of both designs.
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MOPJE027	Beam-based Impedance Characterization of the ALBA Pinger Magnet	impedance, simulation, vacuum, injection	334
	U. Iriso, T.F.G. Günzel ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain H. Bartosik, E. Koukovini-Platia, G. Rumolo CERN, Geneva, Switzerland
	The ALBA pinger magnet consists on two short kickers (for horizontal and vertical planes) installed in a single Titanium coated ceramic vacuum chamber. Single bunch measurements in the vertical plane were performed in the ALBA Synchrotron Light Source before and after the pinger installation, and by comparing the Transverse Mode Coupling Instability (TMCI) thresholds for zero chromaticity, we infer the pinger impedance and compare it with the model predictions. We also perform measurements for negative chromaticities and results are reported in this paper.
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MOPJE028	Detailed Characterization of ALBA Quadrupoles for Beta Function Determination	quadrupole, storage-ring, optics, controls	338
	Z. Martí, J. Campmany, J. Marcos, V. Massana ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain X.N. Gavaldà SOLEIL, Gif-sur-Yvette, France
	Beta function value at quadrupoles for a circular accelerator can be determined using the relationship between the machine tune and the quadrupole strength. ALBA Storage Ring quadrupoles were measured during manufacturing, to be sure that their performance fitted the specifications. However, measurements were done at a number of currents that are not enough for an accurate determination of the beta function value. In fact, at least 1% error in the calibration of the hysteresis curve slope of the quadrupole is required, and therefore new detailed measurements of the hysteresis cycle are needed. In order to make these measurements, spare quadrupoles existing at ALBA have been used. In this paper we present the results of beta function values determination using this method for ALBA storage ring.
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MOPJE046	Influence of the Alignment of the Main Magnets on Resonances in the CERN Proton Synchrotron	resonance, alignment, proton, operation	392
	A. Huschauer, S.S. Gilardoni, R. Wasef CERN, Geneva, Switzerland
	During the Long Shutdown 1 seven out of the one hundred combined function PS main magnets were removed from the tunnel to conduct maintenance. After reinstallation, the main magnets were aligned to the reference positions and within the first week of operation of the accelerator, a beam-based re-alignment campaign was performed to reduce the excursions of the closed orbit. In order to further investigate and understand the source of betatronic resonances, which, already in 2011, were found to be excited by the bare machine, tune diagram measurements before and after this beam-based magnet alignment were conducted. In both cases the same resonances as in 2011 were found to be present; however, after the alignment, an overall increase of their strengths was observed. In this paper we present the corresponding measurement results and discuss the direct impact on the daily operation of the accelerator.
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MOPJE047	Chromaticity Dependence of the Transverse Effective Impedance in the CERN Proton Synchrotron	impedance, proton, controls, space-charge	395
	S. Persichelli, N. Biancacci, S.S. Gilardoni, A. Huschauer, E. Métral, B. Salvant, R. Wasef CERN, Geneva, Switzerland M. Migliorati University of Rome La Sapienza, Rome, Italy
	The current knowledge of the transverse impedance of the Proton Synchrotron (PS) has been established with beam-based measurements at different energies. The transverse coherent tune shift as a function of the beam intensity has been measured in order to evaluate the total effective imaginary part of the transverse impedance and its localization in the accelerator at the energies of 2, 7, 13 and 25 GeV. Measurements have been performed changing the chromaticity for every tune shift scan with intensity. The data analysis revealed an increase of impedance with chromaticity for all the energies considered. That transverse impedance can be compared with the previously evaluated theoretical impedance budget taking into account the individual contribution of several machine devices. The missing impedance is finally highlighted.
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MOPJE057	Optics Measurement using the N-BPM Method for the ALBA Synchrotron	optics, quadrupole, betatron, dipole	430
	A. Langner, J.M. Coello de Portugal, R. Tomás CERN, Geneva, Switzerland G. Benedetti, M. Carlà, U. Iriso, Z. Martí ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	The N-BPM method recently developed for the LHC has significantly improved the precision of optics measurements which are based on beam position monitor (BPM) turn-by-turn data. The main improvement is owed to the consideration of correlations for statistical and systematic error sources, as well as increasing the amount of BPM combinations for one measurement. We present how this technique can be applied at light sources like ALBA, and compare the results with other methods.
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MOPJE066	Single and Multi-bunch End-to-end Tracking in the LHeC	linac, lattice, radiation, synchrotron-radiation	459
	D. Pellegrini, A. Latina, D. Schulte CERN, Geneva, Switzerland S.A. Bogacz JLab, Newport News, Virginia, USA
	The LHeC study aims at delivering an electron beam for collision with the LHC proton beam. The current baseline design consists of a multi-pass superconductive energy-recovery linac operating in a continuous wave mode. The high current beam (~100 mA) in the linacs excites long-range wake-fields between bunches of different turns, which induce instabilities and might cause beam losses. PLACET2, a novel version of the tracking code PLACET, capable to handle recirculation and time dependencies, has been employed to perform the first LHeC end-to-end tracking. The impact of long-range wake-fields, synchrotron radiation, and beam-beam effects has been assessed. The simulation results and recent improvements in the lattice design are presented and discussed in this paper.
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MOPJE072	Simulations and Measurements of Longitudinal Coupled-bunch Instabilities in the CERN PS	feedback, cavity, luminosity, impedance	479
	L. Ventura, H. Damerau, M. Migliorati, G. Sterbini CERN, Geneva, Switzerland M. Migliorati, L. Ventura INFN-Roma1, Rome, Italy M. Migliorati University of Rome La Sapienza, Rome, Italy L. Ventura University of Rome "La Sapienza", Rome, Italy
	Among various and challenging objectives of the LHC Injectors Upgrade project (LIU), one aim is to double the beam intensity of the CERN Proton Synchrotron (PS) in order to achieve the integrated luminosity target of the High-Luminosity LHC project (HL-LHC). A known limitation to reach the required high intensity is caused by the longitudinal coupled-bunch oscillations developing above the transition energy. The unwanted oscillations induce large bunch-to-bunch intensity variations not compatible with the specifications of the future LHC-type beams. A wide-band longitudinal damper has been installed in the PS to suppress these instabilities and is going to be commissioned. A measurement campaign of coupled-bunch oscillations has been launched to substantiate the extrapolations and predictions for the future High Luminosity LHC beam with the final aim to determine the maximum intensity that could be provided to the LHC. In parallel a Simulink© model of the PS is going to be implemented to predict the machine behavior in the parameter space of LIU and to be used during the beam commissioning and optimization of the feedback system.
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MOPMA001	Comparison of Measurements and Simulations for Single Bunch Instabilities at Diamond	impedance, wakefield, radiation, simulation	521
	M. Atay, R. Bartolini JAI, Oxford, United Kingdom R. Bartolini, R.T. Fielder, I.P.S. Martin DLS, Oxfordshire, United Kingdom
	The single bunch dynamics in the Diamond storage ring has been analysed with a multiparticle tracking code and compared with the results of a wealth of diagnostics, including streak camera, Schottky diodes and FTIR spectra. The interplay of various wakefield sources has been studied and it has been found that the THz spectrum can be reproduced in many cases with simple impedance models, both below and above the bursting threshold.
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MOPMA003	Reconstruction of Electron Bunch Motion During CSR Bursts using Synchronised Diagnostics	electron, detector, radiation, storage-ring	529
	I.P.S. Martin, R. Bartolini, C. Bloomer, L.M. Bobb, G. Rehm DLS, Oxfordshire, United Kingdom R. Bartolini, A. Finn JAI, Oxford, United Kingdom
	Above a certain threshold current, electron bunches become unstable and emit bursts of coherent synchrotron radiation (CSR). The character and periodicity of these bursts vary with bunch current, RF voltage and lattice momentum compaction. In this paper we describe recent measurements taken at Diamond of how the electron bunch longitudinal profile and energy vary during a burst, and correlate this with CSR emission at a range of wavelengths.
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MOPMA017	Numerical simulations of transverse modes in Gaussian bunches with space charge	space-charge, damping, simulation, lattice	575
	A. Macridin, J.F. Amundson, E.G. Stern Fermilab, Batavia, Illinois, USA
	The transverse modes and the intrinsic Landau damping in Gaussian bunched beams with space charge are numerically investigated. The evolution of the phase space density is calculated with the Synergia accelerator modeling package and analyzed with Dynamic Mode Decomposition (DMD) method. DMD is a relatively new technique used to calculate mode dynamics in both linear and nonlinear systems. The properties of the first three space charge modes, including their shape, damping rates and tune shifts are calculated over the entire range of the space charge interaction.
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MOPMN004	CSR Impedance for Non-Ultrarelativistic Beams	impedance, wakefield, radiation, space-charge	709
	R. Li JLab, Newport News, Virginia, USA C.-Y. Tsai Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
	Funding: This work is supported by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. For the analysis of the coherent synchrotron radiation (CSR) induced microbunching gain in the low energy regime, such as when a high-brightness electron beam is transported through a low-energy merger in an energy-recovery linac (ERL) design, it is necessary to extend the CSR impedance expression in the ultrarelativistic limit to the non-ultrarelativistic regime. This paper presents our analysis of CSR impedance for general beam energies.
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MOPMN016	Decoherence due to Second Order Chromaticity in the NSLS-II Storage Ring	betatron, storage-ring, damping, lattice	737
	G. Bassi, A. Blednykh, J. Choi, V.V. Smaluk BNL, Upton, Long Island, New York, USA
	We study decoherence effects due to second order chromaticity for small amplitude kicks, in order to estimate the energy spread from TbT data of the NSLS-II storage ring. The bare lattice case (no Damping Wigglers and Insertion devices) has been considered, due to the long transverse radiation damping time. To minimize the chromatic damping/antidamping from the slow-head tail effect, we used a short train of bunches distributed over consecutive rf-buckets with a high enough average current to obtain a good BPM signal. The vertical and horizontal betatron motion have been excited independently with pinger magnets. In this contribution we limit the discussion to the horizontal case.
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MOPMN018	A Generic Formulation for Emittance and Lattice Function Evolution for Non-Hamiltonian Systems with Stochastic Effects	emittance, lattice, radiation, scattering	740
	J.S. Berg BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. I describe a generic formulation for the evolution of emittances and lattice functions under arbitrary, possibly non-Hamiltonian, linear equations of motion. The average effect of stochastic processes, which would include ionization interactions and synchrotron radiation, is also included. I first compute the evolution of the covariance matrix, then the evolution of emittances and lattice functions from that. I examine the particular case of a cylindrically symmetric system, which is of particular interest for ionization cooling.
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MOPMN019	Understanding the Effect of Space Charge on Instabilities	space-charge, impedance, hadron, operation	743
	M. Blaskiewicz BNL, Upton, Long Island, New York, USA A. Chao SLAC, Menlo Park, California, USA Y.H. Chin KEK, Ibaraki, Japan
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The combined effects of space charge and wall impedance on transverse instabilities is an important consideration in the design and operation of hadron machines as well as an intrinsic academic interest. This study explores the combined effects of space charge and wall impedance using various simplified models in an attempt to produce a better understanding of their interplay.
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MOPMN020	Longitudinal Impedance of RHIC	impedance, experiment, storage-ring, scattering	746
	M. Blaskiewicz, J.M. Brennan, K. Mernick BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The longitudinal impedance of the two RHIC rings has been measured using the effect of potential well distortion on longitudinal Schottky measurements. With Z/n about 5 Ω the impedance of the yellow ring is roughly twice that of the blue ring.
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MOPHA001	Transverse Bunch by Bunch Feedback Operations at the Australian Synchrotron Light Source	feedback, operation, resonance, storage-ring	769
	R.T. Dowd, M.P. Atkinson, M.J. Boland, G. LeBlanc, Y.E. Tan, K. Zingre SLSA, Clayton, Australia
	The Australian Synchrotron light source has recently put in operation its transverse bunch-by-bunch feedback system during user beam mode. Getting to the stage of stable operation has been a long road and this paper will outline the many difficulties that were encountered. Chief among these are the apparent strong, high frequency, vertical resonances that appear when the storage ring's three in-vacuum undulators are closed to specific gaps. The behaviour of these resonances and their effects on achieving stable feedback operation will be explored in detail.
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MOPHA009	Single-Shot Electro-Optic Sampling Combined With Photonic Time-Stretch: Detailed Results at SOLEIL	laser, detector, storage-ring, real-time	795
	C. Szwaj, C. Evain, E. Roussel PhLAM/CERLA, Villeneuve d'Ascq, France S. Bielawski PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France J.B. Brubach, L. Cassinari, M.-E. Couprie, M. Labat, L. Manceron, J.P. Ricaud, P. Roy, M.-A. Tordeux SOLEIL, Gif-sur-Yvette, France M. Le Parquier CERLA, Villeneuve d'Ascq, France
	Funding: ANR (DYNACO project), FEDER, CEMPI LABEX. Single-shot recording of pulses is possible with high repetition rates (more than 80 MHz), as was demonstrated in the framework of a PhLAM-SOLEIL collaboration * *. This can be achieved by a relatively simple upgrade of existing setups based on spectral encoding. The strategy consists to encode the sub-picosecond information into the time domain, but at a slower scale (nanoseconds), using dispersion in a long optical fiber. Then the information is recorded by a photodiode connected to an oscilloscope. In this poster, we present guidelines for the practical realization of the electro-optical setup, as well as a performance analysis. In particular, we analyze the temporal resolution and compare it to the classical electro-optical sampling setup. E. Roussel et al., Proceedings of IPAC2014, THOBA01. ** E. Roussel et al., arXiv:1410.7048
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MOPHA010	RF Feedback and Detuning Studies for the BESSY Variable Pulse Length Storage Ring Higher Harmonic SC Cavities	cavity, beam-loading, feedback, operation	798
	A. Neumann, P. Echevarria, P. Goslawski, M. Ries, M. Ruprecht, A.V. Vélez, G. Wüstefeld HZB, Berlin, Germany
	For the feasibility of the BESSY VSR upgrade project of BESSY II two higher harmonic systems at a factor of 3 and 3.5 of the ring's RF fundamental of 500 MHz will be installed in the ring. Operating in continuous wave at high average accelerating field of 20 MV/m and phased at zero-crossing, the superconducting cavities have to be detuned within tight margins to ensure stable operation and low power consumption at a loaded Q of 5·10⁷. The field variation of the cavities is mainly driven by the repetitive transient beam-loading of the envisaged complex bunch fill pattern in the ring. Within this work combined LLRF-cavity and longitudinal beam dynamics simulation will demonstrate the limits for stable operation, especially the coupling between synchrotron oscillation and RF feedback settings. Further impact by beam current decay and top-up injection shots are being simulated. * G. Wüstefeld et al., IPAC 11, San Sebastiàn, Spain, p. 2936.
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MOPHA021	Bunch-by-Bunch Longitudinal RF Feedback for Beam Stabilization at FAIR	feedback, LLRF, controls, cavity	820
	K. Groß, H. Klingbeil TEMF, TU Darmstadt, Darmstadt, Germany U. Hartel, H. Klingbeil, U. Laier, D.E.M. Lens, K.-P. Ningel, S. Schäfer, B. Zipfel GSI, Darmstadt, Germany
	Funding: Work supported by the German Federal Ministry of Education and Research (BMBF) under the project 05P12RDRBF. To damp undesired longitudinal oscillations of bunched beams, the main synchrotron SIS100 of FAIR (Facility for Antiproton and Ion Research) will be equipped with a bunch-by-bunch feedback system. This helps to stabilize the beam, to keep longitudinal emittance blow-up low and to minimize beam losses. The proposed LLRF (low level radio frequency) topology of the closed loop feedback system is described. In some aspects, it is similar to the beam phase control system* developed at GSI Helmholtzzentrum für Schwerionenforschung GmbH. The differences and challenges are pointed out, which are mainly the bunch-by-bunch signal processing followed by the generation of a correction voltage in dedicated feedback cavities. The adapted topology was verified at SIS18 during beam time in 2014 using LLRF prototype subsystems and the two existing ferrite-loaded acceleration cavities. The experimental setup to damp coherent longitudinal dipole oscillations is presented and evaluated with focus on the realized modifications, including ongoing and pending investigations. Finally, the current status of the longitudinal feedback system for FAIR is summarized. * Klingbeil et al., IEEE Trans. Nuc. Sci., Vol. 54, No. 6, 2007.
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MOPHA023	Observation of Coherent Pulses in the Sub-THz Range at DELTA	electron, radiation, detector, laser	823
	C. Mai, F.H. Bahnsen, M. Bolsinger, S. Hilbrich, M. Huck, M. Höner, S. Khan, A. Meyer auf der Heide, R. Molo, H. Rast, G. Shayeganrad, P. Ungelenk DELTA, Dortmund, Germany M. Brosi, B. Kehrer, A.-S. Müller, M.J. Nasse, P. Schönfeldt, P. Schütze, S. Walther KIT, Karlsruhe, Germany H. Huck DESY Zeuthen, Zeuthen, Germany
	Funding: Work supported by the BMBF (05K13PEC). Coherent ultrashort THz pulses induced by a laser-electron interaction are routinely produced and observed at DELTA, a 1.5-GeV synchrotron light source operated by the TU Dortmund University. The turn-by-turn evolution of the radiation spectrum is known to shift to the sub-THz regime after the initial laser-electron interaction. Recently, an ultrafast YBCO-based THz detector has been permanently installed and a Schottky diode has been tested at the THz beamline. Measurements with these detectors showing the temporal evolution of the coherent signals after several revolutions are presented. Furthermore, the concept of a recently designed Fourier-transform spectrometer optimized for the sub-THz region is shown.
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MOPHA037	Visible Light Diagnostics at the ANKA Storage Ring	photon, diagnostics, detector, radiation	866
	B. Kehrer, A. Borysenko, E. Hertle, N. Hiller, M. Holz, A.-S. Müller, P. Schönfeldt, P. Schütze KIT, Karlsruhe, Germany
	Synchrotron radiation in the visible light range is a versatile diagnostics tool for accelerator studies. At the ANKA storage ring of the Karlsruhe Institute of Technology (KIT), we have a dedicated visible light diagnostics beamline and two additional beam ports close to the radiation's source point. The visible light diagnostics beamline hosts a time-correlated single-photon-counting unit to measure the bunch filling pattern and a streak camera for longitudinal diagnostics. Recently, the beamline has been extended with a fast-gated intensified camera to study transverse instabilities. The synchrotron light monitor ports were previously used for direct source imaging. Due to the diffraction limit the vertical beam size could not be resolved. One of the two ports has recently been equipped with a double-slit to allow for interferometric measurements of the vertical beam size. In this paper we give an overview of the different setup modifications and present first results.
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MOPHA039	A Fast Gated Intensified Camera Setup for Transversal Beam Diagnostics at the ANKA Storage Ring	storage-ring, radiation, experiment, bunching	872
	P. Schütze, A. Borysenko, E. Hertle, N. Hiller, B. Kehrer, A.-S. Müller, P. Schönfeldt KIT, Karlsruhe, Germany
	ANKA, the synchrotron light source at Karlsruhe Institute of Technology (KIT), can be operated in different modes including the short bunch operation with bunch lengths compressed to a few picoseconds. In this mode, coherent synchrotron radiation (CSR) is emitted leading to beam instabilities. For gaining further insight into those processes, a setup based on a fast gated intensified camera was installed recently at the visible light diagnostics beamline of the ANKA storage ring. The experimental layout consists of an optical setup, which magnifies the image of the beam in the horizontal and demagnifies it in the vertical plane to obtain a projection of the horizontal beam shape, the camera itself and a fast scanning galvanometric mirror that sweeps this image across the sensor. This allows the tracking of the horizontal bunch size and position over many turns. In this paper we present the setup and show first measurement results.
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MOPHA042	Online Studies of THz-radiation in the Bursting Regime at ANKA	radiation, optics, synchrotron-radiation, bunching	882
	M. Brosi, C.M. Caselle, E. Hertle, N. Hiller, A. Kopmann, A.-S. Müller, M. Schwarz, P. Schönfeldt, J.L. Steinmann, M. Weber KIT, Eggenstein-Leopoldshafen, Germany
	Funding: This work has been supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320 The ANKA storage ring of the Karlsruhe Institute of Technology (KIT) operates in the energy range from 0.5 to 2.5 GeV and generates brilliant coherent synchrotron radiation in the THz range with a dedicated bunch length reducing optic. The producing of radiation in the so-called THz-gap is challenging, but this intense THz radiation is very attractive for certain user experiments. The high degree of compression in this so-called low-alpha optics leads to a complex longitudinal dynamics of the electron bunches. The resulting micro-bunching instability leads to time dependent fluctuations and strong bursts in the radiated THz power. The study of these fluctuations in the emitted THz radiation provides insight into the longitudinal beam dynamics. Fast THz detectors combined with KAPTURE, the dedicated KArlsruhe Pulstaking and Ultrafast Readout Electronics system developed at KIT, allow the simultaneous measurement of the radiated THz intensity for each bunch individually in a multi-bunch environment. This contribution gives an overview of the first experience gained using this setup as an online diagnostics tool.
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MOPHA043	Properties of Transition- and Synchrotron Radiation at FLUTE	radiation, synchrotron-radiation, electron, detector	885
	M. Schwarz, A.-S. Müller KIT, Karlsruhe, Germany M.T. Schmelling MPI-K, Heidelberg, Germany
	FLUTE (Ferninfrarot Linac Und Test Experiment) is a 41 MeV linear accelerator currently under construction at KIT. It is aimed at accelerator physics and THz radiation research. For this reason the machine will cover a wide range of bunch charges (1 pC up to 3 nC) and lengths (1 fs to 300 fs). One aim of FLUTE is the study of different mechanisms for the generation of intense THz pulses, such as transition- (TR) or synchrotron radiation (SR). In this contribution, we calculate and compare various pulse properties, such as spectra, and electric fields, for both TR and SR.
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MOPHA058	Beam Based Gain Calibration for Beam Position Monitor at J-PARC Main Ring	simulation, operation, proton, closed-orbit	927
	H. Kuboki, J. Takano, M. Tejima, T. Toyama KEK, Ibaraki, Japan S. Hatakeyama JAEA/J-PARC, Tokai-mura, Japan
	Funding: MEXT KAKENHI Grant Number 25105002, Grant-in-Aid for Scientific Research on Innovative Areas titled "Unification and Development of the Neutrino Science Frontier" Beam Position Monitor (BPM) is one of the essential elements in a synchrotron facility. It provides the accurate beam positions, which are used to correct the closed orbit distortion. Each BPM is installed with the electronics which enable to acquire the data of the turn-by-turn beam positions. Here, we define the "gain" as the proportionality coefficient between the signal detected at the ADC and the ideal signal without any errors. The signal strength from a BPM electrode varies depending on 1) transmission characteristics of a long cable, 2) processing circuit, and 3) contact resistance at the connected parts. These are the origin of the gain deviations. In order to correct the deviations, a Beam Based Gain Calibration (BBGC) method has been proposed . Development of a new method for adequate gain calibration is required because any calibration method for routine operation has not been established for BPMs with diagonal-cut electrodes used at J-PARC Main Ring. The results of analysis will be presented using the Total Least Square fitting as an adequate method for the BBGC with sufficient accuracy within 0.6% in one standard deviation. M. Tejima et al., DIPAC2011 (2011).
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MOPTY001	Development of Wideband BPM for Precise Measurement of Internal Bunch Motion	impedance, coupling, feedback, network	937
	K.G. Nakamura Kyoto University, Kyoto, Japan Y.H. Chin, T. Koseki, T. Obina, M. Okada, M. Tobiyama, T. Toyama KEK, Ibaraki, Japan Y. Shobuda JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	Funding: This work was supported by MEXT KAKENHI Grant Number 25105002, Grant-in-Aid for Scientific Research on Innovative Areas titled “ Unification and　Development of the Neutrino Science Frontier” To suppress intra-bunch oscillations and to reduce particle losses, the intra-bunch feedback (IBFB) system has been developed in 2014 for the J-PARC Main Ring (MR). A new BPM was also installed to the MR for the IBFB system. This BPM has a sufficient frequency response and position sensitivity(up to 1.5GHz within 15% fluctuation ). However, a better performance may be needed in future for more precise analysis of internal motions (e.g. due to an electron cloud). We report the development of the BPM and precise measurement results of the BPM characteristics. We also report simulation studies of the digital equalizer which helps to reconstructs the beam shape from beam signals.
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MOPTY003	Measurement of Momentum Spread of the Injection Beam with Longitudinal Tomography Method in the J-PARC RCS	linac, injection, acceleration, operation	944
	M. Yoshimoto, H. Harada, H. Hotchi, M. Kinsho, P.K. Saha, F. Tamura, M. Yamamoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	In the J-PARC RCS, the beam tuning toward the design output beam power of 1MW were started after the completing of the beam energy and beam current upgrades in the LINAC. One of the important issues to achieve the 1MW beam operation is the optimization of the injection beam from the LINAC. Due to the longitudinal beam tuning in the LINAC, the momentum spread of the injected beam into the RCS was measured with the longitudinal tomography method. Our longitudinal tomography tool had been developed using the simple algorithm with the Convolution Back-Projection (CBP) method for the beam storage mode of the RCS. Accordingly, we improved this tool to expand into the acceleration mode.
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MOPTY019	Precise Position Measurement by Analyzing the Correlation Between Electrodes of a Single Bpm	simulation, pick-up, hardware, impedance	975
	Z.C. Chen SSRF, Shanghai, People's Republic of China L.W. Lai, Y.B. Leng, Y.B. Yan SINAP, Shanghai, People's Republic of China
	Beam position is one of the most important parameters in a particle accelerator. The more accurate and precise the measurement system is, the more features of the beam dynamics could be revealed. A method called model-independent analysis (MIA) takes advantage of multiple beam position monitors (BPM) on the storage ring to obtain the actual beam positions by removing the random noise of each BPM. Inspired by MIA, the original voltage waveforms obtained from the electrodes of a single BPM can also be decomposed to get the beam position information. This article discusses the results of the experiments and the evaluation of the performance of the BPM at the Shanghai Institute of Applied Physics.
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MOPTY028	Introduction to BINP HLS to Measure Vertical Changes on PAL-XFEL Buildings and Ground	alignment, operation, laser, ground-motion	994
	H. J. Choi, K.H. Gil, H.-S. Kang, S.H. Kim, K.W. Seo PAL, Pohang, Kyungbuk, Republic of Korea
	PAL-XFEL is being installed and will be completed by December of 2015 so that users can be supported beginning in 2016. PAL-XFEL equipment should continuously maintain the bunch beam parameter. To this end, PAL-XFEL equipment has to be kept precisely aligned. As a part of the process for installing PAL-XFEL, a surface geodetic network and the installation of a tunnel measurement network inside buildings is in preparation; additionally, the fiducialization of major equipment is underway. After PAL-XFEL equipment is optimized and aligned, if the ground and buildings go through vertical changes during operation, misalignment of equipments will cause errors in the electron beam trajectory, which will lead to changes to the beam parameter. For continuous and systemic measurement of vertical changes in buildings and to monitor ground sinking and uplifting, the BINP Ultrasonic-type Hydrostatic Levelling System (HLS) is to be installed and operated in all sections of PAL-XFEL for linear accelerator, Undulator and beam line. This study will introduce the operation principle, design concept and advantages (self-calibration) of HLS, and will outline its installation plan and operation plan.
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MOPTY030	Capacitive Linear-Cut Beam Position Monitor Design for Ion Synchrotron at KHIMA Project	vacuum, target, operation, proton	998
	J.G. Hwang, C.H. Kim, S.H. Nam, S.Y. Noh KIRAMS/KHIMA, Seoul, Republic of Korea G. Hahn, W.T. Hwang, T.K. Yang KIRAMS, Seoul, Republic of Korea E.-S. Kim Kyungpook National University, Daegu, Republic of Korea
	The KHIMA (Korea Heavy Ion Medical Accelerator) project is launched to construct the carbon and proton beam base ion therapy machine. It, which consists of the injector with RFQ and IH-DTL linacs, medium beam transport line, synchrotron, and high energy beam transport line, will be provided the carbon beam up to 430 MeV/u and proton beam up to 230 MeV for cancer therapy. The high precision beam position monitor is required to match and control the beam trajectory for the beam injection and closed orbit in synchrotron. It was also used for measuring the beta-function, tune, and chromaticity. Since the bunch length at heavy ion synchrotron is relatively long, a few meters, a box-like device with long plates of typically 20 cm is used to enhance the signal strength and to get a precise linear dependence with respect to the beam displacement. In this presentation, we show the electromagnetic design of the electrode and surroundings to satisfy the resolution of 100 um, the criteria for mechanical aspect to satisfy the position accuracy of 200 um, the measurement result of position accuracy by using the wire test-bench, and the beam-test results with long (~ 1.6 us) electron beam in PAL.
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MOPTY042	ALBA LLRF Upgrades to Improve Beam Availability	cavity, LLRF, beam-loading, operation	1022
	A. Salom, B. Bravo, J. Marcos, F. Pérez ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	ALBA is a 3GeV synchrotron light source located in Barcelona and operating with users since May 2012. The RF system of the SR is composed of six cavities, each one powered by combining the power of two 80 kW IOTs through a Cavity Combiner (CaCo). At present, there are several RF interlocks per week. The redundancy given by the six cavities makes possible the survival of the beam after one of these trips. In these cases, the cavity has to be recovered with the circulating beam. An autorecovery process has been implemented in the digital LLRF system in order to recover the faulty RF plant after a trip. But these trips also create perturbations to the beam stability. In order to minimize the beam perturbations induced by these RF interlock, an additional feed-forward loop is being implemented. The functionally, main parameters and test results of these new algorithms will be presented.
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MOPTY073	Commissioning of BPM System for TPS Booster Synchrotron	booster, electronics, injection, storage-ring	1106
	P.C. Chiu, Y.-S. Cheng, K.T. Hsu, K.H. Hu, C.H. Kuo NSRRC, Hsinchu, Taiwan
	The TPS is a latest generation of high brightness synchrotron light source and ready for commissioning. It consists of a 150 MeV electron linac, a booster synchrotron, a 3 GeV storage ring, and experimental beam lines. The BPM electronics Libera Brilliance⁺ are adopted for booster and storage ring of Taiwan Photon Source (TPS). The provided BPM data is useful for beam commissioning where it can be used to measure beam position, rough beam intensity along the longitudinal position and also for tune measurement. This report summarizes the efforts on BPM measurement and related diagnostic tools during TPS booster commissioning.
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MOPTY074	Preliminary Beam Test of Synchrotron Radiation Monitoring System at Taiwan Photon Source	storage-ring, booster, radiation, synchrotron-radiation	1109
	C.Y. Liao, Y.-S. Cheng, J. -Y. Chuang, K.T. Hsu, S.Y. Hsu, H.P. Hsueh, K.H. Hu, C.K. Kuan, C.Y. Wu NSRRC, Hsinchu, Taiwan
	Taiwan Photon Source (TPS) is a third generation 3 GeV synchrotron light facility. The synchrotron radiation from a dipole can be used to observe the beam parameters. The synchrotron radiation monitor (SRM) systems were designed and implemented for the booster synchrotron and storage ring. The SRM for the booster synchrotron can serve to diagnose the energy ramping process. The beam size decreases when the energy increases was observed. In the storage ring, the streak camera was preferred to observe the beam behaviour of the consecutive bunches. The bunch length and longitudinal instability were observed. The preliminary beam test results are summarized in this report.
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MOPTY080	A Multi-band Single Shot Spectrometer for Observation of mm-Wave Bursts at Diamond Light Source	detector, storage-ring, radiation, synchrotron-radiation	1126
	A. Finn, P. Karataev JAI, Egham, Surrey, United Kingdom G. Rehm DLS, Oxfordshire, United Kingdom
	Micro-bunch instabilities (MBI) have been detected at many light sources across the world. The radiation bursts produced as a result of this instability occur in the millimetre wavelength regime. In order to understand more about the mechanism of MBI and improve the accuracy of simulations, more information is needed about the dynamics and spectral content of the radiation. A single shot spectrometer has therefore been developed to investigate this instability at Diamond Light Source. Due to their low noise, ultra-fast response and excellent sensitivity, Schottky detector diodes are employed. Currently, seven Schottky detectors are in place covering a range of 33-750 GHz. Unlike previous measurements at Diamond, each of the Schottky detectors has been characterised thus allowing the results obtained to be more easily compared to simulations. In this paper, we present the calibration of each Schottky detector in the spectrometer, the first results of tests with beam, as well as future plans for the spectrometer.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPTY080
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MOPWI002	Bunch Length Measurements using Synchrotron Light Monitor	linac, emittance, injection, dipole	1143
	M.M. Ali, M.G. Tiefenback JLab, Newport News, Virginia, USA
	The bunch length is measured at CEBAF using an invasive technique. The technique depends on applying an energy chirp for the electron bunch and imaging it through a dispersive region. The measurements are taken through Arc1 and Arc2 at CEBAF. The fundamental equations, procedure and the latest results are given.
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MOPWI031	Microwave Modeling for Electron Cloud Density Measurements at CesrTA	simulation, resonance, electron, storage-ring	1227
	J.P. Sikora, Y. Li Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA S. De Santis LBNL, Berkeley, California, USA
	Funding: This work is supported by the US National Science Foundation PHY-0734867, PHY-1002467, and the US Department of Energy DE-FC02-08ER41538, DE-SC0006505. The electron cloud (EC) density in accelerator beam-pipe has been measured using resonant microwaves. The resonances are produced by changes in beam-pipe geometry that generate reflections and standing waves, with typical behavior being similar to a section of waveguide with shorted ends. The technique uses fact that the EC density will shift the resonant frequencies. In previous analysis, we have made the simplifying approximation that the standing waves are multiples of a half-wavelength and that the magnitude of the electric field is symmetric about the longitudinal center of the resonance. In this paper we show that some changes in beam-pipe geometry will result in asymmetric electric field magnitudes along the resonant length. When this is combined with an EC density that varies along this length, the magnitude of the frequency shift will be altered. We present our initial attempt to correct for this effect by modeling the existing beam-pipe using CST Microwave Studio(R) to obtain a more realistic electric field distribution. This correction is then applied to data taken with beam at several resonant frequencies. The measurements were made at the Cornell Electron Storage Ring (CESR), which has been reconfigured as a test accelerator (CesrTA) providing electron or positron beams ranging in energy from 2 to 5 GeV. * http://dx.doi.org/10.1016/j.nima.2014.03.063
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MOPWI035	Characterization of Visible Synchrotron Radiation Polarization at SPEAR3	polarization, radiation, synchrotron-radiation, diagnostics	1240
	W.J. Corbett, A.M. Kiss SLAC, Menlo Park, California, USA M.J. Boland The University of Melbourne, Melbourne, Victoria, Australia C.L. Li East China University of Science and Technology, Shanghai, People's Republic of China
	Schwinger's equations predict the angular- and spectral distribution of synchrotron radiation across a wide band of the electromagnetic spectrum. Using a visible-light diagnostic beam line, it is possible to characterize the electric field polarization state as a function of vertical observation angle and compare with theory. Complications include accounting for - and π-mode transmission factors at mirror surfaces and precise alignment of the polarizing optics with the principle beam axes. The Stokes parameters are measured and beam polarization ellipse reported.
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MOPWI041	Identification of Intra-Bunch Transverse Dynamics for Model Based Wideband Feedback Control at CERN Super Proton Synchrotron	controls, feedback, simulation, proton	1249
	O. Turgut, J.E. Dusatko, J.D. Fox, C.H. Rivetta SLAC, Menlo Park, California, USA W. Höfle CERN, Geneva, Switzerland
	Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515 and the US LHC Accelerator Research program (LARP). Multi-input multi-output (MIMO) feedback design techniques can be helpful to stabilize intra-bunch transverse instabilities induced by electron-clouds or transverse mode couplings at the CERN Super Proton Synchrotron (SPS). These MIMO techniques require a reduced order model of intra-bunch dynamics. We estimate a linear reduced order MIMO models for transverse intra-bunch dynamics and use these models to design model based MIMO feedback controllers. The effort is motivated by the plans to increase currents in the SPS as part of the HL-LHC upgrade. Parameters of the reduced order models are estimated based on driven beam SPS measurements. We study different types of controllers. We test the model based designs using macro particle simulation codes (CMAD and HEADTAIL) and compare its performance with FIR filters tested during beam measurements of the feedback system in SPS machine development (MD) studies.
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MOPWI046	eDT and Model-based Configuration of 12 GeV CEBAF	operation, controls, radiation, linac	1259
	D.L. Turner JLab, Newport News, Virginia, USA
	Funding: Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. This poster will discuss model-driven setup of CEBAF for the 12GeV era, focusing on the elegant Download Tool (eDT). eDT is a new operator tool that generates magnet design setpoints for various machine energies and pass configurations. eDT was developed in the effort towards a process for reducing machine configuration time and reproducibility by way of an accurate accelerator model.
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MOPWI052	Responsivity Study of Diamond X-ray Monitors with nUNCD Contact	photon, detector, plasma, database	1273
	M. Gaowei, J. Smedley BNL, Upton, Long Island, New York, USA E.M. Muller, T. Zhou SBU, Stony Brook, New York, USA A.V. Sumant Argonne National Laboratory, Center for Nanoscale Materials, Argonne, USA
	Nitrogen doped ultrananocrystalline diamond (nUNCD) grown on the surface of a CVD single crystal diamond is tested at various beamlines covering an x-ray photon energy range of 200eV to 28 keV. The nUNCD has much lower x-ray absorption than metal contacts and is designed to improve the performance of our device. The responsivity of nUNCD diamond x-ray detector is compared with the conventional platinum coated diamond x-ray beam position monitor and the results are presented in this paper.
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TUXC2	Engineering Challenges of Future Light Sources	storage-ring, vacuum, feedback, emittance	1308
	R.T. Neuenschwander, L. Liu, S.R. Marques, A.R.D. Rodrigues, R.M. Seraphim LNLS, Campinas, Brazil
	We review some of the present engineering challenges associated with the design and construction of ultra-low emittance storage rings, the 4th generation storage rings (4GSR). The field is experiencing a growing interest since MAX-IV, followed by Sirius, started to build storage rings based on multi-bend-achromat (MBA) lattices. It was the recent progress in accelerator technology that allowed these facilities to base their designs on this kind of lattice. Although the challenges are starting to be overcome, many issues are still open and a lot of R&D is required until the 4GSR achieve optimal performance.
	Slides TUXC2 [7.022 MB]
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TUXC3	Commissioning of the Taiwan Photon Source	booster, storage-ring, quadrupole, emittance	1314
	C.-C. Kuo, C.-T. Chen, J.Y. Chen, M.-S. Chiu, P.J. Chou, K.T. Hsu, Y.C. Liu, G.-H. Luo, H.-J. Tsai, F.H. Tseng NSRRC, Hsinchu, Taiwan
	The Taiwan Photon Source (TPS) is a 3-GeV third-generation synchrotron light source located in Hsinchu, Taiwan. After ground breaking on February 7, 2010 and five years of construction and hardware developments, commissioning of the beam began on December 12, 2014. The booster ring reached the design energy of 3 GeV on December 16. Beam transferred to the storage ring and first accumulation at 3 GeV produced the first synchrotron light on December 31. This report presents results and experience of the TPS commissioning.
	Slides TUXC3 [5.425 MB]
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TUAC1	Beam Instrumentation and Diagnostics for High Luminosity LHC	radiation, diagnostics, pick-up, collimation	1349
	O.R. Jones, E. Bravin, B. Dehning, T. Lefèvre, H. Schmickler CERN, Geneva, Switzerland
	The extensive array of beam instrumentation with which the LHC is equipped, has played a major role in its commissioning, rapid intensity ramp-up and safe and reliable operation. High Luminosity LHC (HL-LHC) brings with it a number of new challenges in terms of instrumentation that will be discussed in this contribution. The beam loss system will need significant upgrades in order to be able to cope with the demands of HL-LHC, with cryogenic beam loss monitors under investigation for deployment in the new inner triplet magnets to distinguish between primary beam losses and collision debris. Radiation tolerant integrated circuits are also being developed to allow the front-end electronics to sit much closer to the detector. Upgrades to other existing systems are also envisaged; including the beam position measurement system in the interaction regions and the addition of a halo measurement capability to synchrotron light diagnostics. Additionally, several new diagnostic systems are under investigation, such as very high bandwidth pick-ups and a streak camera installation, both able to perform intra-bunch measurements of transverse position on a turn by turn basis.
	Slides TUAC1 [4.490 MB]
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TUPWA001	Measurement of the Incoherent Depth of Field Effect on Horizontal Beam Size Using a Synchrotron Light Interferometer	electron, photon, storage-ring, lattice	1391
	M.J. Boland SLSA, Clayton, Australia W.J. Corbett SLAC, Menlo Park, California, USA T.M. Mitsuhashi KEK, Ibaraki, Japan
	The electron beam size as measured using synchrotron light in a circular accelerator is influenced by the incoherent depth of field effect. This effect comes about due to the instantaneous opening angle of the emitted synchrotron radiation (SR) and the acceptance angle of the SR light monitor beamline. Measurements were made using a visible light interferometer at the visible light beamlines in three circular accelerators at ATF, SPEAR3 and AS. The first order spatial coherence of the beam was measured and from that the horizontal beam size was calculated. The data is compared with a theory of synchrotron radiation with and without the horizontal incoherent field depth effect.
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TUPWA004	Operator Roles at the Australian Synchrotron	operation, controls, database, storage-ring	1397
	D.C. McGilvery ASCo, Clayton, Victoria, Australia G. LeBlanc SLSA, Clayton, Australia
	The Accelerator Operators at the Australian Synchrotron undertake a wide variety of critical functions as part of their regular duties. In addition to normal Control Room duties, they play a major Role in Machine Physics, provide after hours support for Users on Beamlines and contribute extensively to the Controls and Database Development across the facility.
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TUPWA005	Comparison of Bunch Compression Schemes for the AXXS FEL	linac, simulation, FEL, electron	1399
	T.K. Charles, D.M. Paganin Monash University, Faculty of Science, Clayton, Victoria, Australia A.A. Aksoy Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey M.J. Boland, R.T. Dowd SLSA, Clayton, Australia A. Latina, D. Schulte CERN, Geneva, Switzerland
	Different types of electron bunch compression schemes are compared for the AXXS FEL design study. The main linac for the proposed machine is based on CLIC x-band structures. This choice leaves several options for the bunch compression schemes which impact the injection system RF band. Both harmonic linearization and phase modulation linearization are considered and their relative strengths and weaknesses compared. Simulations were performed to compare the performance of an s-band injector with a higher harmonic RF linearization and an x-band injector. One motivation for the study is to optimise the length of the AXXS machine, allowing the linac to fit onto the proposed and also act as the injector to the existing storage ring at the Australian Synchrotron.
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TUPWA021	A New Method to Generate Ultrashort and Coherent Pulses of Short-Wavelength Synchrotron Radiation	laser, electron, radiation, storage-ring	1448
	S. Khan DELTA, Dortmund, Germany
	Funding: Work supported by the BMBF (contract 05K13PE3) A laser-based method to generate ultrashort pulses of synchrotron radiation in electron storage rings is coherent harmonic generation (CHG) using two undulators to produce coherent radiation at harmonics of the initial laser wavelength by microbunching. The bunching factor and thus the pulse intensity, however, decreases exponentially with increasing harmonic order. Echo-enabled harmonic generation (EEHG), proposed in 2009 as FEL seeding scheme, can be used to produce short synchrotron radiation pulses at higher harmonics, but requires three undulators in a straight section. In this paper, a less space-consuming method based on seeding with intensity-modulated laser pulses is introduced, which also has the potential of significant bunching factors at high harmonics. G. Stupakov, PRL 102 (2009), 074801.
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TUPWA022	Characterization and Optimization of Ultrashort and Coherent VUV Pulses at the DELTA Storage Ring	laser, electron, radiation, undulator	1452
	S. Khan, F.H. Bahnsen, M. Bolsinger, S. Hilbrich, M. Huck, M. Höner, C. Mai, A. Meyer auf der Heide, R. Molo, H. Rast, G. Shayeganrad, P. Ungelenk DELTA, Dortmund, Germany H. Huck DESY Zeuthen, Zeuthen, Germany
	Funding: Work supported by BMBF (05K13PE3 and 05K13PEC), DFG (INST 212/236-1 FUGG) and the Land NRW At DELTA, a 1.5-GeV synchrotron light source operated by the TU Dortmund University, a source for coherent and ultrashort vacuum-ultraviolet (VUV) and terahertz (THz) pulses is now in operation. The VUV source is based on a laser-induced energy modulation and coherent harmonic generation (CHG). A subsequently developing dip in the longitudinal electron distribution gives rise to coherent THz radiation. Recent results regarding the optimization of the laser-electron interaction and characterization of the CHG pulses are presented.
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TUPWA025	Beam Heat Load Analysis with COLDDIAG: A Cold Vacuum Chamber for Diagnostics	electron, storage-ring, diagnostics, vacuum	1459
	R. Voutta, S. Casalbuoni, S. Gerstl, A.W. Grau, T. Holubek, D. Saez de Jauregui KIT, Eggenstein-Leopoldshafen, Germany R. Bartolini, M.P. Cox, E.C. Longhi, G. Rehm, J.C. Schouten, R.P. Walker DLS, Oxfordshire, United Kingdom M. Migliorati, B. Spataro INFN/LNF, Frascati (Roma), Italy
	The knowledge of the heat intake from the electron beam is essential to design the cryogenic layout of superconducting insertion devices. With the aim of measuring the beam heat load to a cold bore and understanding the responsible mechanisms, a cold vacuum chamber for diagnostics (COLDDIAG) has been built. The instrumentation comprises temperature sensors, pressure gauges, mass spectrometers and retarding field analyzers, which allow to study the beam heat load and the influence of the cryosorbed gas layer. COLDDIAG was installed in the storage ring of the Diamond Light Source from September 2012 to August 2013. During this time measurements were performed for a wide range of machine conditions, employing the various measuring capabilities of the device. Here we report on the analysis of the measured beam heat load, pressure and gas content, as well as the low energy charged particle flux and spectrum as a function of the electron beam parameters.
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TUPWA028	Simulation Results of the Beam Transport of Ultra-Short Electron Bunches in Existing Beam Transfer Lines to Sinbad	linac, optics, gun, electron	1466
	U. Dorda, R.W. Aßmann, K. Flöttmann, B. Marchetti, Y.C. Nie, J. Zhu DESY, Hamburg, Germany
	SINBAD, the upcoming accelerator R&D facility at DESY, will host multiple independent experiments on the production and acceleration of ultra-short bunches including plasma wakefield experiments. As a possible later upgrade the option to transport higher energy electrons (up to 800 MeV) or positrons (up to 400 MeV) from the existing DESY Linac 2 to the facility is studied. Though existing a possible connection using e.g. a part of the DESY synchrotron as a transfer line and other currently unused transfer-line, these machines were not designed for the desired longitudinal bunch compression and high peak current required by e.g. beam driven plasma wake-field experiments. Simulation results illustrate the modifications to the current layout that would have to be implemented and the corresponding achievable beam parameters are given.
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TUPWA034	Status of the Recommissioning of the Synchrotron Light Source PETRA III	emittance, lattice, operation, optics	1485
	R. Wanzenberg, M. Bieler, M. Ebert, L. Fröhlich, J. Keil, J. Klute, G. Kube, G.K. Sahoo DESY, Hamburg, Germany
	At DESY the Synchrotron Light Source PETRA III has been extended in the North and East section of the storage ring to accommodate ten additional beam lines. The PETRA ring was converted into a dedicated synchrotron light source from 2007 to 2009. Regular user operation started in summer 2010 with a very low emittance of 1 nm at a beam energy of 6 GeV and a total beam current of 100 mA. All photon beamlines were installed in one octant of the storage ring. Nine straight sections facilitated the installation of insertion devices for 14 beam lines. Due to the high demand for additional beamlines the lattice of the ring was redesigned to accommodate 10 additional beamlines in the future. In a one year long shut-down two new experimental halls were built. The recommissioning of PETRA III started in February 2015. We are reporting the current status of synchrotron light source including the performance of the subsystems.
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TUPWA043	Non-interferometric Spectral Analysis of Synchrotron Radiation in the THz regime at ANKA	radiation, synchrotron-radiation, electron, storage-ring	1509
	J.L. Steinmann, M. Brosi, E. Bründermann, C.M. Caselle, E. Hertle, N. Hiller, B. Kehrer, A.-S. Müller, M. Schuh, M. Schwarz, P. Schönfeldt, P. Schütze KIT, Karlsruhe, Germany J.L. Hesler Virginia Diodes Inc., Charlottesville, USA
	Interferometry is the quasi-standard for spectral measurements in the THz- and IR-range. The frequency resolution, however, is limited by the travel range of the interferometer mirrors. Therefore, a resolution in the low megahertz range would require interferometer arms of about 100 m. As an alternative, heterodyne measurements provide a resolution in the Hertz range, an improvement of 6 orders of magnitude. Here we present measurements done at ANKA with a VDI WR3.4SAX, a mixer that can be tuned to frequencies from 220 GHz to 330 GHz and we show how the bunch filling pattern influences the amplitude of specific frequencies.
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TUPJE005	Development of Pulsed Multipole Magnet for Aichi SR Storage Ring	storage-ring, electron, injection, multipole	1616
	K. Ito, M. Hosaka, A. Mano, T. Takano, Y. Takashima Nagoya University, Nagoya, Japan K. Hayashi, M. Katoh UVSOR, Okazaki, Japan N. Yamamoto KEK, Ibaraki, Japan
	The Aichi synchrotron radiation (Aichi SR) center is an industrial oriented synchrotron light source facility. The electron energy and circumference of the storage ring are 1.2 GeV and 72 m. The natural emittance is 53 nm-rad. Since the pulsed multipole injection scheme provides great advantages for relatively smaller SR rings, we are developing a pulsed multipole injection system for Aichi SR storage ring. In this system, it is essential to minimize the perturbation to the stored beam. To realize the required performances, we have to minimize the residual field at stored beam position, taken into account the field generated by the copper current lead of the input terminal. In addition, we carried out the analytical calculation to estimate the magnet field due to the current lead and optimized the geometrical structure of them. Construction of the multipole magnet will be completed in March 2015 and the field measurement will be carried out in April. In this presentation, we report the detail of the magnet design and the measurement results of pulsed magnetic field for the manufactured magnet. N. Yamamoto, et. al., NIM A 767, 26-33 (2014)
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TUPJE006	Recent Developments of UVSOR-III	undulator, injection, laser, operation	1619
	M. Katoh, K. Hayashi, J. Yamazaki UVSOR, Okazaki, Japan M. Adachi, T. Konomi, N. Yamamoto KEK, Ibaraki, Japan M. Hosaka, Y. Takashima Nagoya University, Nagoya, Japan
	A 750 MeV low energy synchrotron light source, UVSOR, has been operational since 1983. About ten years after the first major upgrade in 2003, the second major upgrade was carried out in 2012, in which all the bending magnets were replaced with combined function ones and a new in-vacuum undulator was installed in the last straight section reserved for undulators. After this upgrade, the light source, UVSOR-III, has been operational with small emittance of 17 nm-rad, with six undulators, and fully with the top-up injection at 300mA. Adding to the present status of the accelerator, most recent progresses in the pulsed sextupole magnet for the beam injection and in the coherent light source development station will be presented.
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TUPJE012	Preliminary Result of Photon Counting Acquisition Scheme for Laser Pump/X-ray Probe Experiments	laser, experiment, detector, timing	1638
	J. He, J.S. Cao, G. Gao, Y.F. Sui, Y. Tao, J.H. Yue, Z. Zhang, Y.F. Zhou IHEP, Beijing, People's Republic of China
	Funding: This work is supported by the NSFC under grant No.11305186 R&D project has been initiated for a proposed ultralow emittance (~50pm.rad) synchrotron light source built in Beijing. The R&D includes the development of high repetition rate laser pump/X-ray probe for ultrafast dynamics detection in future source. In a typical laser pump/X-ray probe measurement, the X-ray pulse follows a laser pulse in adjustable delay. We are interested in the difference between laser on and laser off at different delay, which will snapshot dynamic process. To capture this trivial difference, it requires the acquisition system to single out the signal from this special X-ray pulse at adequate S/N ratio. For the R&D of high repetition rate pump-probe, we have set up a prototype counting acquisition system based on NIM modular electronics, which was tested in Beijing Synchrotron Radiation Facility (BSRF). The laser will be synchronized with a camshaft bunch at 124 kHz, a tenth of the revolution frequency. Avalanche Photo Diode (APD) was used to detect the X-ray pulse from this camshaft bunch due to its nanosecond response. Before the laser is delivered, we mimic the 124 kHz laser- on signal. The signals from APD are separated by power dividers into two Constant Fraction Discriminator (CFD) input channels. The signal in laser-on/off channel is gated out at 1.24MHz using the 1.24MHz timing signal divided from 499.8 MHz RF signal, while the mimic laser-on signal gated out at 124 kHz. Multiplied by ten times, the mimic laser-on signal counts should be consistent with the laser-on+off counts, if our counting modular works well. We carried out this test at 1W1B wiggler beam line to measure the Fe fluorescence signal. The performance of our system is demonstrated in the good consistency between mimic laser on and laser on+off signals.
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TUPJE016	COHERENT SYNCHROTRON RADIATION FIELD AND THE ENERGY LOSS IN A WAVY BEAM	electron, radiation, wakefield, synchrotron-radiation	1650
	D.R. Xu, H. Xu USTC/NSRL, Hefei, Anhui, People's Republic of China
	The synchrotron radiation will be coherent when the wavelength of the radiation can be compared with the bunch length. There are two approaches to produce Coherent Synchrotron Radiation (CSR) on a storage ring. One is to compress the bunch length, the other one is to produce a wavy beam which has high spatial repetition along the longitudinal direction. The latter one can expand the radiation frequency range of a light source. However, CSR can bring nonlinear effect which brings in extra instability. The Lienard-Wiechert potentials in three-dimensional space may have very complicated forms. The most common way to investigate CSR is numerical method. This paper try to use a simple model to obtain energy loss of the electrons in theory.
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TUPJE018	On-axis Injection Scheme for Ultimate Storage Ring with Double RF Systems	injection, emittance, storage-ring, radiation	1657
	B.C. Jiang, S.Q. Tian, M.Z. Zhang, Q.L. Zhang, Z.T. Zhentang SINAP, Shanghai, People's Republic of China
	An on-axis injection scheme using double RF systems for an ultimate storage ring which holds very small dynamic aperture is proposed. By altering RF voltages, empty RF buckets can be created which will be used for on-axis injection. After bunches are injected, a reverse voltage altering process is performed and the injected bunches can be longitudinally dumped to the main buckets.
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TUPJE035	Optimization of Turn-by-Turn Measurements at Soleil and Alba Light Sources	quadrupole, lattice, betatron, storage-ring	1686
	M. Carlà, G. Benedetti, Z. Martí ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain L.S. Nadolski SOLEIL, Gif-sur-Yvette, France
	Turn-by-turn measurements paves the way for fast storage ring diagnostics. On the other hand turn-by-turn technique is by its very nature delicate, requiring an extensive system tuning and understanding. During last year several attempts to recover linear model informations from turn-by-turn measurements has been carried out in cooperation between the synchrotrons of SOLEIL and ALBA. A routine to extract phase advance and betatron amplitude from turn-by-turn measurements in presence of damping has been developed. Moreover a procedure to retrieve quadrupole errors from such observables has been developed tested and verified against the traditional diagnostics tools based on closed orbit measurements. A comparison between the different methods and the performance of the two different experimental setups are reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE035
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TUPJE036	A New Bench Concept for Measuring Magnetic Fields of Big Closed Structures	controls, operation, vacuum, alignment	1690
	J. Campmany, F. Becheri, C. Colldelram, J. Marcos, V. Massana, J. Nicolás, L. Ribó ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	The measurement of big closed magnetic structures is becoming a challenge of great interest. The main reason is the tendency towards building accelerators with high magnetic fields produced by small gap magnets, as well as the development of cryogenic or superconducting narrow-gap insertion devices. Usual approach, based on side-measurements made with a Hall probe mounted on the tip of a motorized arm based on a long granite bench is no more applicable to such closed structures. So, new concepts and approaches have been developed, mainly based on complex devices that insert a Hall probe inside the magnetic structure maintaining the desired position by close-loop controls. The main problem of these devices is that they are not general-purpose oriented: they need a special vacuum chamber, require a specific geometry of the magnetic structure, or does not provide 3D field-map measurements. We present in this paper a new bench that has been built at ALBA synchrotron that is simple, multi-purpose and can be a general solution for measuring big closed structures.
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TUPJE053	Hardware Improvements and Beam Commissioning of the Booster Ring in Taiwan Photon Source	booster, hardware, linac, injection	1741
	H.-J. Tsai, C.-T. Chen, J.Y. Chen, M.-S. Chiu, P.C. Chiu, P.J. Chou, K.T. Hsu, K.H. Hu, C.-C. Kuo, Y.-C. Liu, G.-H. Luo, F.H. Tseng NSRRC, Hsinchu, Taiwan
	Taiwan Photon Source (TPS), a low emittance 3-GeV third-generation synchrotron light source, began its hardware integration testing, safety checkout and beam commissioning on August 12, 2014 [1]. The booster ring and the storage ring share the same tunnel in a concentric fashion; the booster ring has circumference 496.8 m, the largest among light source facilities in operation. A combined-function FODO lattice is adopted for the booster ring with natural emittance 10 nm-rad. After hardware improvements were completed, the commissioning of the beam in the booster ring began on December 12 and attained the 3-GeV design energy on December 16.
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TUPJE057	Realistic Undulators for Intense Gamma-ray Beams at Future Colliders	undulator, electron, positron, simulation	1756
	A.O. Alrashdi, I.R. Bailey Lancaster University, Lancaster, United Kingdom D. Newton The University of Liverpool, Liverpool, United Kingdom
	The baseline designs for the ILC and CLIC require the production of an intense flux of gamma rays in their positron sources. In the case of CLIC the gamma rays are produced by a Compton backscattering source, but in this paper we concentrate on undulator-based sources as proposed for the ILC. We present the development of a simulation to generate a magnetic field map based on a Fourier analysis of any measured field map. We have used a field map measured from the ILC helical undulator prototype to calculate the typical distribution of field errors, and used them in our calculations to produce simulated field maps. We show that a loss of gamma ray intensity of ~ 8% could be expected, compared to the ideal case. This leads to a similar drop in positron production which can be compensated for by increasing the undulator length.
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TUPMA035	Control of Synchrotron Radiation Effects during Recirculation	emittance, controls, recirculation, lattice	1913
	D. Douglas, S.V. Benson, A.S. Hofler, R. Kazimi, R. Li, Y. Roblin, C. Tennant JLab, Newport News, Virginia, USA G.A. Krafft, B. Terzić ODU, Norfolk, Virginia, USA C.-Y. Tsai Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177. Numerous proposals invoke recirculation and/or energy recovery for cost-performance optimization. These often encounter challenges with the beam-quality-degrading effects of incoherent and coherent synchrotron radiation (ISR and CSR). We describe a means of controlling of this degradation. The approach utilizes results by diMitri et al. , and invokes behavior observed during simulations of the recirculation process. The method is based on the use of periodically isochronous 2nd-order achromats; this not only insures that the conditions for the suppression of CSR-driven emittance growth are met, it also suppresses micro-bunching gain over a broad range of parameter space . Details of specific designs will be presented, and a reference to an analysis of micro-bunching effects provided. A planned test of the CSR suppression mechanism in CEBAF will be described. S. diMitri et al., Phys. Rev. Lett. 110, 014801, 2 January 2013. *C.Y. Tsai et al., these proceedings.
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TUPMA057	Commissioning of Active Interlock System for NSLS II Storage Ring	storage-ring, radiation, synchrotron-radiation, photon	1962
	S. Seletskiy, C. Amundsen, J. Choi, J.H. De Long, K.M. Ha, C. Hetzel, H.-C. Hseuh, Y. Hu, P. Ilinski, S.L. Kramer, Y. Li, M.A. Maggipinto, J. Mead, D. Padrazo, T.V. Shaftan, G. Shen, O. Singh, R.M. Smith, W.H. Wahl, G.M. Wang, F.J. Willeke, L. Yang BNL, Upton, Long Island, New York, USA
	The NSLS-II storage ring is protected from possible damage from insertion devices (IDs) synchrotron radiation by a dedicated active interlock system (AIS). It monitors electron beam position and angle and triggers beam drop if beam orbit exceeds the boundaries of pre-calculated active interlock envelope. In this paper we describe functional details of the AIS and discuss our experience with commissioning of the AIS for the first six IDs installed in the storage ring.
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TUPTY031	Tools for Flexible Optimisation of IR Designs with Application to FCC	radiation, synchrotron-radiation, simulation, detector	2072
	H. Burkhardt CERN, Geneva, Switzerland M. Boscolo INFN/LNF, Frascati (Roma), Italy
	The interaction regions of future high-luminosity colliders require well balanced designs, which provide both for a very high luminosity and at the same time keep backgrounds and radiation at tolerable levels. We describe a set of flexible tools, targeted at providing a first evaluation of losses in the interaction region as part of the design studies, and their application to FCC.
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TUPTY058	Mitigating Performance Limitations of Single Beam-pipe Circular e⁺e⁻ Colliders	luminosity, collider, electron, operation	2160
	M. Koratzinos DPNC, Genève, Switzerland F. Zimmermann CERN, Geneva, Switzerland
	Renewed interest in circular e⁺e⁻ colliders has spurred designs of single beam-pipe machines, like the CEPC in China, and double beam pipe ones, such as the FCC-ee effort at CERN. Single beam-pipe designs profit from lower costs but are limited by the number of bunches that can be accommodated in the machine. We analyse these performance limitations and propose a solution that can accommodate O(1000) bunches while keeping more than 90% of the ring with a single beam pipe.
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TUPTY060	The FCC-ee Study: Progress and Challenges	collider, interaction-region, radiation, optics	2165
	M. Koratzinos DPNC, Genève, Switzerland S. Aumon, C. Cook, A. Doblhammer, B. Härer, B.J. Holzer, R. Tomás, F. Zimmermann CERN, Geneva, Switzerland A.V. Bogomyagkov, E.B. Levichev, D.N. Shatilov BINP SB RAS, Novosibirsk, Russia M. Boscolo INFN/LNF, Frascati (Roma), Italy L.E. Medina Medrano UGTO, Leon, Mexico U. Wienands SLAC, Menlo Park, California, USA
	The FCC (future circular collider) study represents a vision for the next large project in high energy physics, comprising a 80-100 km tunnel that can house a future 100TeV hadron collider. The study also includes a high luminosity e⁺e⁻ collider operating in the centre-of-mass energy range of 90-350 GeV as a possible intermediate step, the FCC-ee. The FCC-ee aims at definitive electro-weak precision measurements of the Z, W, H and top particles, and search for rare phenomena. Although FCC-ee is based on known technology, the goal performance in luminosity and energy calibration make it quite challenging. During 2014 the study went through an exploration phase and during the next three years a conceptual design report will be prepared.
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TUPTY077	Strong-Strong Beam-Beam Simulation of Bunch Length Splitting at the LHC	simulation, emittance, resonance, beam-beam-effects	2210
	J. Qiang, S. Paret LBNL, Berkeley, California, USA K. Ohmi KEK, Ibaraki, Japan T. Pieloni CERN, Geneva, Switzerland

Paper

Title

Other Keywords

Page

MOBB1

Status of the Proton Beam Commissioning at the MedAustron Ion Beam Therapy Centre

injection, proton, acceleration, extraction

28

A. Garonna, M. Kronberger, T.K.D. Kulenkampff, C. Kurfürst, F. Osmić, L.C. Penescu, M.T.F. Pivi, C. Schmitzer, P. Urschütz, A. Wastl
EBG MedAustron, Wr. Neustadt, Austria

The MedAustron accelerator, located in Wiener Neustadt (Austria), will deliver clinical beams of protons (60-250 MeV) and carbon ions (120-400 MeV/n) to three ion beam therapy irradiation rooms (IR). Clinical beams and proton beams up to 800 MeV will be provided in a fourth IR, dedicated to non-clinical research. A slow-extracted proton beam of maximum clinical energy has been delivered for the first time in IR3 in October 2014, thus providing the technical proof-of-principle of the accelerator chain. The recent related beam commissioning efforts included setting up of the multi-turn injection into the synchrotron at 7 MeV, the acceleration on first harmonic up to 250 MeV, the slow extraction on the third integer resonance with a betatron core and the matching of the High Energy Beam Transfer line. The accelerator optimization phase leading to IR3 medical commissioning of proton beams is ongoing. The main characteristics of the MedAustron accelerator system will be presented, along with the results obtained during the commissioning process.

Slides MOBB1 [6.596 MB]

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MOBC2

High-Performance Simulations of Coherent Synchrotron Radiation on Multicore GPU and CPU Platforms

GPU, simulation, electron, radiation

42

B. Terzić, A.L. Godunov
ODU, Norfolk, Virginia, USA
A. Arumugam, D. Ranjan, M. Zubair
ODU CS, Norfolk, Virginia, USA

Coherent synchrotron radiation (CSR) is an effect of self-interaction of an electron bunch as it traverses a curved path. It can cause a significant emittance degradation and microbunching. We present a new high-performance 2D, particle-in-cell code which uses massively parallel multicore GPU/GPU platforms to alleviate computational bottlenecks. The code formulates the CSR problem from first principles by using the retarded scalar and vector potentials to compute the self-interaction fields. The speedup due to the parallel implementation on GPU/CPU platforms exceeds three orders of magnitude, thereby bringing a previously intractable problem within reach. The accuracy of the code is verified against analytic 1D solutions (rigid bunch).

Slides MOBC2 [4.866 MB]

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MOAD3

Relative Alignment Within the MAX IV 3 GeV Storage Ring Magnet Blocks

alignment, storage-ring, magnet-design, quadrupole

57

J.H. Björklund Svensson, M.A.G. Johansson
MAX-lab, Lund, Sweden

Unlike the discrete magnet scheme of previous 3rd generation light sources, the magnet elements of the MAX IV storage rings are integrated in precision-machined magnet blocks. By analyzing the rotating coil measurements made by the magnet suppliers, we determined the relative alignment between consecutive magnet elements, which was found to be <10 microns RMS for all magnet block types in both horizontal and vertical direction. This article presents our analysis and results for the full magnet production series.

Slides MOAD3 [1.825 MB]

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MOPWA011

The Damping of Transverse Coherent Instabilities by Harmonic Cavities

betatron, simulation, damping, electron

102

F.J. Cullinan, R. Nagaoka
SOLEIL, Gif-sur-Yvette, France
G. Skripka, P.F. Tavares
MAX-lab, Lund, Sweden

At nonzero chromaticity, the threshold current due to transverse coupled bunch instabilities in an electron storage ring is defined by intrabunch head-tail motion of higher than zeroth order. Multibunch tracking simulations predict that this threshold can be increased to several times its original value through the introduction of bunch lengthening harmonic cavities. One previously suggested explanation is the narrower spectra of the elongated bunches but reliable estimates for the threshold currents are not obtainable for anything other than rigid beam motion since the usual Sacherer formulism is not directly applicable to beams in a non-harmonic potential. A new scheme has been developed in which the decay time of a higher than zeroth order transverse head-tail mode may be estimated by taking into account the synchrotron tune spread generated by the harmonic cavity potential. This scheme is presented along with the results of numerical simulations performed in order to confirm the analytical predictions and justify the assumptions made. The extension of the scheme to more complex scenarios is also discussed.

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MOPWA013

Modeling and Measurements of Spin Depolarization

kicker, electron, resonance, polarization

109

N. Carmignani, F. Ewald, L. Farvacque, B. Nash, P. Raimondi
ESRF, Grenoble, France

An electron bunch in a storage ring becomes spin polarized due to the Sokolov-Ternov effect. The beam may then be depolarized by applying a horizontal magnetic field oscillating in resonance with the spin tune. This technique has been used to measure the electron energy at numerous synchrotrons. In this paper, we report on modeling and measurements of the polarization and depolarization process at the ESRF. We report the results of a Matlab based parallelized spin tracking code that we developed for these studies. We show the change in depolarization resulting as different physical effects are added to the model.

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MOPWA020

Longitudinal Stability Of Short Bunches in Storage Rings with Strong Longitudinal Focusing

impedance, dipole, simulation, resonance

135

P. Kuske
HZB, Berlin, Germany

Funding: work supported by the BMBF
In the BESSY VSR project, the variable bunch length storage ring, two high gradient accelerating structures at 1.5 and 1.75 GHz will be phased such that long and short bunches can be stored simultaneously. The longitudinal stability of the short bunches is investigated taking into account the shielded CSR- and a purely inductive impedance. Multi particle tracking studies and numerical solutions of the Vlasov-Fokker-Planck equation show that threshold currents for short bunches do not follow the simple scaling law which was found for long bunches. The inductive impedance can even lower the thresholds for the instability. With an 80 times increased accelerating gradient and reasonable assumptions on the inductive impedance for shorter bunches stable operation can be expected with bunches 1.8 ps long (RMS-value) and 0.8 mA current. According to the calculations and operating in a dedicated low-α mode will produce stable 40 μA bunches with 400 fs length

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MOPWA022

Influence of Transient Beam Loading on the Longitudinal Beam Dynamics at BESSY VSR

beam-loading, damping, simulation, cavity

141

M. Ruprecht, P. Goslawski, A. Jankowiak, A. Neumann, M. Ries, G. Wüstefeld
HZB, Berlin, Germany
T. Weis
DELTA, Dortmund, Germany

BESSY VSR, a scheme where 1.7 ps and 15 ps long bunches (rms) can be stored simultaneously in the BESSY II storage ring has recently been proposed *. The strong longitudinal bunch focusing is achieved by superconducting high gradient RF cavities. If the bunch fill pattern exhibits a significant inhomogeneity, e.g. due to gaps, transient beam loading causes a distortion of the longitudinal phase space which is different for each bunch. The result are variations along the fill pattern in synchronous phase, synchrotron frequency and bunch shape. This paper presents investigations of transient beam loading and depicts the consequences on bunch length, phase stability and longitudinal multi-bunch oscillations for the projected setup of BESSY VSR.
* G. Wüstefeld, A. Jankowiak, J. Knobloch, M. Ries, Simultaneous Long and Short Electron Bunches in the BESSY II Storage Ring, Proceedings of IPAC2011, San Sebastián, Spain

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MOPWA023

Preserving Information of the Three Spatial Electron Beam Dimensions in One Streak Camera Measurement

operation, electron, photon, diagnostics

144

M.T. Switka, W. Hillert
ELSA, Bonn, Germany

Funding: Work funded by the DFG within SFB/TRR16
At the pulse stretcher ring ELSA, a streak camera is used for the analysis of visible synchrotron radiation. It functions as fast time resolving beam diagnostic apparatus capable of visualizing dynamics down to the picosecond time range. The optical beamline splits the photon beam and projects the electron beam's image onto the streak camera with transversely perpendicular orientation and slight displacement, thereby providing simultaneous imaging of both transverse planes. Thus, the information of bunch and beam dynamics in three dimensions is preserved and can be observed in slow sweep or synchroscan operation. Characteristics and exemplary measurements, demonstrating the capabilities and limits of this technique, are presented.

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MOPWA024

Estimation of the Ion Density in Accelerators using the Beam Transfer Function Technique

ion, electron, betatron, impedance

147

D. Sauerland, W. Hillert
ELSA, Bonn, Germany
A. Meseck
HZB, Berlin, Germany

Funding: Funded by the federal ministry of education and science of Germany
The ELSA stretcher ring of Bonn University serves external hadron physics experiments with a quasi continuous electron beam of up to 3.2 GeV energy. Ions, being generated by collisions of the circulating electrons with the residual gas molecules, accumulate inside the beam potential, causing incoherent tune shifts and coherent beam instabilities. Detailed measurements were carried out in which ion dynamics is studied in dependence of beam energy and current, filling patterns and bias voltages of the ion clearing electrodes. By measuring the beam transfer function using a broadband transversal kicker, we were able to derive an estimate of the average ion density from the shift and broadening of the tune peak. In this contribution first results of these measurements are presented.

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MOPWA025

Simulation of Laser Cooling of Heavy Ion Beams at High Intensities

laser, ion, scattering, simulation

150

L. Eidam, O. Boine-Frankenheim, D.F.A. Winters
GSI, Darmstadt, Germany

In the past the principle of Doppler laser cooling was investigated and verified in storage rings in the low energy regime. Within the FAIR project the laser cooling will be applied to high intensity and high energy beams for the first time. The laser cooling results in a further increase of the longitudinal phase space density and in non-Gaussian longitudinal beam profiles. In order to ensure stable operation and optimize the cooling process the interplay of the laser force and high intensity effects has to be studied numerically. This contribution will identify constrains of the cooling scheme for an efficient reduction of momentum spread. For high beam energies the scattering of photons has to be treated stochastically instead of using averaged forces. The modeling of the laser force in a particle in cell tracking code will be discussed.

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MOPWA026

Demonstration of Flat Ion Beam Creation and Injection into a Synchrotron

emittance, solenoid, injection, ion

153

L. Groening, S. Appel, L.H.J. Bozyk, Y. El Hayek, M.T. Maier, C. Xiao
GSI, Darmstadt, Germany

At GSI an ion beam with different horizontal and vertical emittances has been created from a beam with initially equal emittances. This round-to-flat adoption has been accomplished without any beam loss. In the set-up the beam passes through a stripping foil placed inside a solenoid followed by a skewed quadrupole triplet. The amount of beam flatness has been controlled by setting the solenoid field strength only. Increase of the product of the two transverse emittances is purely due to the stripping process that occurs anyway along an ion linac. Beams with different amounts of flatness were injected into a synchrotron applying horizontal multi-turn injection. The efficiency of injection increased as smaller as the horizontal emittance was set by the round-to-flat adaptor.

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MOPWA034

Coupled-Bunch Instability Suppression Using RF Phase Modulation at the DELTA Storage Ring

damping, storage-ring, electron, feedback

179

M. Sommer, M. Höner, B.D. Isbarn, S. Khan, B. Riemann, T. Weis
DELTA, Dortmund, Germany

Funding: Work supported by the BMBF under contract no. 05K13PEB
The upcoming upgrade of BESSY II, called BESSY-VSR*, involves the utilization of superconducting multicell RF-resonators with high accelerating gradients to provide short and long bunches in an electron storage ring simultaneously. Even under the assumption of strongest available damping of beam induced modes, the residual impedances of the cavities may cause collective multibunch instabilities at the frontier of stability available from current bunch-by-bunch feedback systems. At the DELTA electron storage ring, a phase modulation of the driving RF is used to suppress coupled-bunch instabilities and to increase the lifetime. The time dependent frequency variation in the order of the synchrotron frequency gives rise to additional damping of the bunch oscillators by decoherence and Landau damping. The behaviour and the additional damping of the bunch oscillators is investigated by the existing bunch-by-bunch feedback system e.g. the increase of the overall damping might support the capability of feedback systems under extreme operating conditions of BESSY-VSR.
* G. Wüstefeld et al., Proc. of IPAC'11, San Sebastián, THPC014

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MOPWA039

Emittance Reduction Possibilities in the PETRA III Magnet Lattice

optics, emittance, sextupole, lattice

197

N. Golubeva, V. Balandin, W. Decking, R. Wanzenberg
DESY, Hamburg, Germany

PETRA III is a third generation light source that has been operated as a user facility since 2010 at DESY. An upgrade for additional beam lines has been carried out, and the recommissioning of the new beam lines is starting in spring 2015. In order to fully exploit the potential of the existing magnet lattice of the PETRA III ring, we present a study of beam optics modifications enabling the reduction of the horizontal emittance without changes of the lattice.

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MOPWA041

Investigation of Radiation Damage of Insertion Devices at PETRA III due to Particle Losses using Tracking Results with SixTrack

radiation, undulator, insertion, insertion-device

203

G.K. Sahoo, M. Bieler, J. Keil, A. Kling, G. Kube, M. Tischer, R. Wanzenberg
DESY, Hamburg, Germany

PETRA-III is a 3rd generation synchrotron light source dedicated to users at 14 beam lines with 30 instruments since 2009. This operates in 40, 60, 480 or 960 bunches with 100 mA at an electron beam energy of 6 GeV. The horizontal beam emittance is 1nmrad while a coupling of 1% amounts to a vertical emittance of 10 pm-rad. The low emittance is achieved by deploying 80m of damping wigglers in two sections in west and north. Some of these undulators and wiggler devices have accumulated total radiation doses of about 100 kGy. Visible corrosion at the magnet structures of some permanent magnet undulators is seen. High dose rate measured regularly by Thermo Luminescent Dosimeters (TLDs) are monitored, which lead to inspect the magnetic field of all insertion devices in the PETRA tunnel. We are investigating particle losses with tracking simulation using SixTrack to gain a certain understanding of the radiation damage of the insertion devices. The goal is to develop a strategy to safeguard the insertion devices from further radiation damage.

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MOPWA055

Study of Emittance Growth Caused by Space Charge and Lattice Induced Resonances

resonance, space-charge, lattice, emittance

245

K. Ohmi
KEK, Ibaraki, Japan

Resonance strength and resonance width induced by space charge and lattice nonlinearity is discussed with integrals along a ring like the radiation integrals. Emittance growth is evaluated by model with the resonance width to understand the mechanism. The results are compared with fully PIC simulations.

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MOPWA059

Dynamic Aperture Studies for the FCC-ee

lattice, sextupole, collider, radiation

258

L.E. Medina Medrano
DCI-UG, León, Mexico
R. Martin, R. Tomás, F. Zimmermann
CERN, Geneva, Switzerland
R. Martin
Humboldt University Berlin, Berlin, Germany

Funding: Work supported by the Beam Project (CONACYT, Mexico).
Dynamic aperture (DA) studies have been conducted on the latest Future Circular Collider - ee (FCC-ee) lattices as a function of momentum deviation. Two different schemes for the interaction region are used, which are connected to the main arcs: the crab waist approach, developed by BINP, and an update to the CERN design where the use of crab cavities is envisioned. The results presented show an improvement in the performance of both designs.

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MOPJE027

Beam-based Impedance Characterization of the ALBA Pinger Magnet

impedance, simulation, vacuum, injection

334

U. Iriso, T.F.G. Günzel
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
H. Bartosik, E. Koukovini-Platia, G. Rumolo
CERN, Geneva, Switzerland

The ALBA pinger magnet consists on two short kickers (for horizontal and vertical planes) installed in a single Titanium coated ceramic vacuum chamber. Single bunch measurements in the vertical plane were performed in the ALBA Synchrotron Light Source before and after the pinger installation, and by comparing the Transverse Mode Coupling Instability (TMCI) thresholds for zero chromaticity, we infer the pinger impedance and compare it with the model predictions. We also perform measurements for negative chromaticities and results are reported in this paper.

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MOPJE028

Detailed Characterization of ALBA Quadrupoles for Beta Function Determination

quadrupole, storage-ring, optics, controls

338

Z. Martí, J. Campmany, J. Marcos, V. Massana
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
X.N. Gavaldà
SOLEIL, Gif-sur-Yvette, France

Beta function value at quadrupoles for a circular accelerator can be determined using the relationship between the machine tune and the quadrupole strength. ALBA Storage Ring quadrupoles were measured during manufacturing, to be sure that their performance fitted the specifications. However, measurements were done at a number of currents that are not enough for an accurate determination of the beta function value. In fact, at least 1% error in the calibration of the hysteresis curve slope of the quadrupole is required, and therefore new detailed measurements of the hysteresis cycle are needed. In order to make these measurements, spare quadrupoles existing at ALBA have been used. In this paper we present the results of beta function values determination using this method for ALBA storage ring.

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MOPJE046

Influence of the Alignment of the Main Magnets on Resonances in the CERN Proton Synchrotron

resonance, alignment, proton, operation

392

A. Huschauer, S.S. Gilardoni, R. Wasef
CERN, Geneva, Switzerland

During the Long Shutdown 1 seven out of the one hundred combined function PS main magnets were removed from the tunnel to conduct maintenance. After reinstallation, the main magnets were aligned to the reference positions and within the first week of operation of the accelerator, a beam-based re-alignment campaign was performed to reduce the excursions of the closed orbit. In order to further investigate and understand the source of betatronic resonances, which, already in 2011, were found to be excited by the bare machine, tune diagram measurements before and after this beam-based magnet alignment were conducted. In both cases the same resonances as in 2011 were found to be present; however, after the alignment, an overall increase of their strengths was observed. In this paper we present the corresponding measurement results and discuss the direct impact on the daily operation of the accelerator.

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MOPJE047

Chromaticity Dependence of the Transverse Effective Impedance in the CERN Proton Synchrotron

impedance, proton, controls, space-charge

395

S. Persichelli, N. Biancacci, S.S. Gilardoni, A. Huschauer, E. Métral, B. Salvant, R. Wasef
CERN, Geneva, Switzerland
M. Migliorati
University of Rome La Sapienza, Rome, Italy

The current knowledge of the transverse impedance of the Proton Synchrotron (PS) has been established with beam-based measurements at different energies. The transverse coherent tune shift as a function of the beam intensity has been measured in order to evaluate the total effective imaginary part of the transverse impedance and its localization in the accelerator at the energies of 2, 7, 13 and 25 GeV. Measurements have been performed changing the chromaticity for every tune shift scan with intensity. The data analysis revealed an increase of impedance with chromaticity for all the energies considered. That transverse impedance can be compared with the previously evaluated theoretical impedance budget taking into account the individual contribution of several machine devices. The missing impedance is finally highlighted.

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MOPJE057

Optics Measurement using the N-BPM Method for the ALBA Synchrotron

optics, quadrupole, betatron, dipole

430

A. Langner, J.M. Coello de Portugal, R. Tomás
CERN, Geneva, Switzerland
G. Benedetti, M. Carlà, U. Iriso, Z. Martí
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

The N-BPM method recently developed for the LHC has significantly improved the precision of optics measurements which are based on beam position monitor (BPM) turn-by-turn data. The main improvement is owed to the consideration of correlations for statistical and systematic error sources, as well as increasing the amount of BPM combinations for one measurement. We present how this technique can be applied at light sources like ALBA, and compare the results with other methods.

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MOPJE066

Single and Multi-bunch End-to-end Tracking in the LHeC

linac, lattice, radiation, synchrotron-radiation

459

D. Pellegrini, A. Latina, D. Schulte
CERN, Geneva, Switzerland
S.A. Bogacz
JLab, Newport News, Virginia, USA

The LHeC study aims at delivering an electron beam for collision with the LHC proton beam. The current baseline design consists of a multi-pass superconductive energy-recovery linac operating in a continuous wave mode. The high current beam (~100 mA) in the linacs excites long-range wake-fields between bunches of different turns, which induce instabilities and might cause beam losses. PLACET2, a novel version of the tracking code PLACET, capable to handle recirculation and time dependencies, has been employed to perform the first LHeC end-to-end tracking. The impact of long-range wake-fields, synchrotron radiation, and beam-beam effects has been assessed. The simulation results and recent improvements in the lattice design are presented and discussed in this paper.

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MOPJE072

Simulations and Measurements of Longitudinal Coupled-bunch Instabilities in the CERN PS

feedback, cavity, luminosity, impedance

479

L. Ventura, H. Damerau, M. Migliorati, G. Sterbini
CERN, Geneva, Switzerland
M. Migliorati, L. Ventura
INFN-Roma1, Rome, Italy
M. Migliorati
University of Rome La Sapienza, Rome, Italy
L. Ventura
University of Rome "La Sapienza", Rome, Italy

Among various and challenging objectives of the LHC Injectors Upgrade project (LIU), one aim is to double the beam intensity of the CERN Proton Synchrotron (PS) in order to achieve the integrated luminosity target of the High-Luminosity LHC project (HL-LHC). A known limitation to reach the required high intensity is caused by the longitudinal coupled-bunch oscillations developing above the transition energy. The unwanted oscillations induce large bunch-to-bunch intensity variations not compatible with the specifications of the future LHC-type beams. A wide-band longitudinal damper has been installed in the PS to suppress these instabilities and is going to be commissioned. A measurement campaign of coupled-bunch oscillations has been launched to substantiate the extrapolations and predictions for the future High Luminosity LHC beam with the final aim to determine the maximum intensity that could be provided to the LHC. In parallel a Simulink© model of the PS is going to be implemented to predict the machine behavior in the parameter space of LIU and to be used during the beam commissioning and optimization of the feedback system.

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MOPMA001

Comparison of Measurements and Simulations for Single Bunch Instabilities at Diamond

impedance, wakefield, radiation, simulation

521

M. Atay, R. Bartolini
JAI, Oxford, United Kingdom
R. Bartolini, R.T. Fielder, I.P.S. Martin
DLS, Oxfordshire, United Kingdom

The single bunch dynamics in the Diamond storage ring has been analysed with a multiparticle tracking code and compared with the results of a wealth of diagnostics, including streak camera, Schottky diodes and FTIR spectra. The interplay of various wakefield sources has been studied and it has been found that the THz spectrum can be reproduced in many cases with simple impedance models, both below and above the bursting threshold.

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MOPMA003

Reconstruction of Electron Bunch Motion During CSR Bursts using Synchronised Diagnostics

electron, detector, radiation, storage-ring

529

I.P.S. Martin, R. Bartolini, C. Bloomer, L.M. Bobb, G. Rehm
DLS, Oxfordshire, United Kingdom
R. Bartolini, A. Finn
JAI, Oxford, United Kingdom

Above a certain threshold current, electron bunches become unstable and emit bursts of coherent synchrotron radiation (CSR). The character and periodicity of these bursts vary with bunch current, RF voltage and lattice momentum compaction. In this paper we describe recent measurements taken at Diamond of how the electron bunch longitudinal profile and energy vary during a burst, and correlate this with CSR emission at a range of wavelengths.

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MOPMA017

Numerical simulations of transverse modes in Gaussian bunches with space charge

space-charge, damping, simulation, lattice

575

A. Macridin, J.F. Amundson, E.G. Stern
Fermilab, Batavia, Illinois, USA

The transverse modes and the intrinsic Landau damping in Gaussian bunched beams with space charge are numerically investigated. The evolution of the phase space density is calculated with the Synergia accelerator modeling package and analyzed with Dynamic Mode Decomposition (DMD) method. DMD is a relatively new technique used to calculate mode dynamics in both linear and nonlinear systems. The properties of the first three space charge modes, including their shape, damping rates and tune shifts are calculated over the entire range of the space charge interaction.

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MOPMN004

CSR Impedance for Non-Ultrarelativistic Beams

impedance, wakefield, radiation, space-charge

709

R. Li
JLab, Newport News, Virginia, USA
C.-Y. Tsai
Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA

Funding: This work is supported by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
For the analysis of the coherent synchrotron radiation (CSR) induced microbunching gain in the low energy regime, such as when a high-brightness electron beam is transported through a low-energy merger in an energy-recovery linac (ERL) design, it is necessary to extend the CSR impedance expression in the ultrarelativistic limit to the non-ultrarelativistic regime. This paper presents our analysis of CSR impedance for general beam energies.

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MOPMN016

Decoherence due to Second Order Chromaticity in the NSLS-II Storage Ring

betatron, storage-ring, damping, lattice

737

G. Bassi, A. Blednykh, J. Choi, V.V. Smaluk
BNL, Upton, Long Island, New York, USA

We study decoherence effects due to second order chromaticity for small amplitude kicks, in order to estimate the energy spread from TbT data of the NSLS-II storage ring. The bare lattice case (no Damping Wigglers and Insertion devices) has been considered, due to the long transverse radiation damping time. To minimize the chromatic damping/antidamping from the slow-head tail effect, we used a short train of bunches distributed over consecutive rf-buckets with a high enough average current to obtain a good BPM signal. The vertical and horizontal betatron motion have been excited independently with pinger magnets. In this contribution we limit the discussion to the horizontal case.

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MOPMN018

A Generic Formulation for Emittance and Lattice Function Evolution for Non-Hamiltonian Systems with Stochastic Effects

emittance, lattice, radiation, scattering

740

J.S. Berg
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
I describe a generic formulation for the evolution of emittances and lattice functions under arbitrary, possibly non-Hamiltonian, linear equations of motion. The average effect of stochastic processes, which would include ionization interactions and synchrotron radiation, is also included. I first compute the evolution of the covariance matrix, then the evolution of emittances and lattice functions from that. I examine the particular case of a cylindrically symmetric system, which is of particular interest for ionization cooling.

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MOPMN019

Understanding the Effect of Space Charge on Instabilities

space-charge, impedance, hadron, operation

743

M. Blaskiewicz
BNL, Upton, Long Island, New York, USA
A. Chao
SLAC, Menlo Park, California, USA
Y.H. Chin
KEK, Ibaraki, Japan

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The combined effects of space charge and wall impedance on transverse instabilities is an important consideration in the design and operation of hadron machines as well as an intrinsic academic interest. This study explores the combined effects of space charge and wall impedance using various simplified models in an attempt to produce a better understanding of their interplay.

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MOPMN020

Longitudinal Impedance of RHIC

impedance, experiment, storage-ring, scattering

746

M. Blaskiewicz, J.M. Brennan, K. Mernick
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The longitudinal impedance of the two RHIC rings has been measured using the effect of potential well distortion on longitudinal Schottky measurements. With Z/n about 5 Ω the impedance of the yellow ring is roughly twice that of the blue ring.

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MOPHA001

Transverse Bunch by Bunch Feedback Operations at the Australian Synchrotron Light Source

feedback, operation, resonance, storage-ring

769

R.T. Dowd, M.P. Atkinson, M.J. Boland, G. LeBlanc, Y.E. Tan, K. Zingre
SLSA, Clayton, Australia

The Australian Synchrotron light source has recently put in operation its transverse bunch-by-bunch feedback system during user beam mode. Getting to the stage of stable operation has been a long road and this paper will outline the many difficulties that were encountered. Chief among these are the apparent strong, high frequency, vertical resonances that appear when the storage ring's three in-vacuum undulators are closed to specific gaps. The behaviour of these resonances and their effects on achieving stable feedback operation will be explored in detail.

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MOPHA009

Single-Shot Electro-Optic Sampling Combined With Photonic Time-Stretch: Detailed Results at SOLEIL

laser, detector, storage-ring, real-time

795

C. Szwaj, C. Evain, E. Roussel
PhLAM/CERLA, Villeneuve d'Ascq, France
S. Bielawski
PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
J.B. Brubach, L. Cassinari, M.-E. Couprie, M. Labat, L. Manceron, J.P. Ricaud, P. Roy, M.-A. Tordeux
SOLEIL, Gif-sur-Yvette, France
M. Le Parquier
CERLA, Villeneuve d'Ascq, France

Funding: ANR (DYNACO project), FEDER, CEMPI LABEX.
Single-shot recording of pulses is possible with high repetition rates (more than 80 MHz), as was demonstrated in the framework of a PhLAM-SOLEIL collaboration * **. This can be achieved by a relatively simple upgrade of existing setups based on spectral encoding. The strategy consists to encode the sub-picosecond information into the time domain, but at a slower scale (nanoseconds), using dispersion in a long optical fiber. Then the information is recorded by a photodiode connected to an oscilloscope. In this poster, we present guidelines for the practical realization of the electro-optical setup, as well as a performance analysis. In particular, we analyze the temporal resolution and compare it to the classical electro-optical sampling setup.
* E. Roussel et al., Proceedings of IPAC2014, THOBA01.
** E. Roussel et al., arXiv:1410.7048

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MOPHA010

RF Feedback and Detuning Studies for the BESSY Variable Pulse Length Storage Ring Higher Harmonic SC Cavities

cavity, beam-loading, feedback, operation

798

A. Neumann, P. Echevarria, P. Goslawski, M. Ries, M. Ruprecht, A.V. Vélez, G. Wüstefeld
HZB, Berlin, Germany

For the feasibility of the BESSY VSR upgrade project of BESSY II two higher harmonic systems at a factor of 3 and 3.5 of the ring's RF fundamental of 500 MHz will be installed in the ring. Operating in continuous wave at high average accelerating field of 20 MV/m and phased at zero-crossing, the superconducting cavities have to be detuned within tight margins to ensure stable operation and low power consumption at a loaded Q of 5·10⁷. The field variation of the cavities is mainly driven by the repetitive transient beam-loading of the envisaged complex bunch fill pattern in the ring. Within this work combined LLRF-cavity and longitudinal beam dynamics simulation will demonstrate the limits for stable operation, especially the coupling between synchrotron oscillation and RF feedback settings. Further impact by beam current decay and top-up injection shots are being simulated.
* G. Wüstefeld et al., IPAC 11, San Sebastiàn, Spain, p. 2936.

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MOPHA021

Bunch-by-Bunch Longitudinal RF Feedback for Beam Stabilization at FAIR

feedback, LLRF, controls, cavity

820

K. Groß, H. Klingbeil
TEMF, TU Darmstadt, Darmstadt, Germany
U. Hartel, H. Klingbeil, U. Laier, D.E.M. Lens, K.-P. Ningel, S. Schäfer, B. Zipfel
GSI, Darmstadt, Germany

Funding: Work supported by the German Federal Ministry of Education and Research (BMBF) under the project 05P12RDRBF.
To damp undesired longitudinal oscillations of bunched beams, the main synchrotron SIS100 of FAIR (Facility for Antiproton and Ion Research) will be equipped with a bunch-by-bunch feedback system. This helps to stabilize the beam, to keep longitudinal emittance blow-up low and to minimize beam losses. The proposed LLRF (low level radio frequency) topology of the closed loop feedback system is described. In some aspects, it is similar to the beam phase control system* developed at GSI Helmholtzzentrum für Schwerionenforschung GmbH. The differences and challenges are pointed out, which are mainly the bunch-by-bunch signal processing followed by the generation of a correction voltage in dedicated feedback cavities. The adapted topology was verified at SIS18 during beam time in 2014 using LLRF prototype subsystems and the two existing ferrite-loaded acceleration cavities. The experimental setup to damp coherent longitudinal dipole oscillations is presented and evaluated with focus on the realized modifications, including ongoing and pending investigations. Finally, the current status of the longitudinal feedback system for FAIR is summarized.
* Klingbeil et al., IEEE Trans. Nuc. Sci., Vol. 54, No. 6, 2007.

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MOPHA023

Observation of Coherent Pulses in the Sub-THz Range at DELTA

electron, radiation, detector, laser

823

C. Mai, F.H. Bahnsen, M. Bolsinger, S. Hilbrich, M. Huck, M. Höner, S. Khan, A. Meyer auf der Heide, R. Molo, H. Rast, G. Shayeganrad, P. Ungelenk
DELTA, Dortmund, Germany
M. Brosi, B. Kehrer, A.-S. Müller, M.J. Nasse, P. Schönfeldt, P. Schütze, S. Walther
KIT, Karlsruhe, Germany
H. Huck
DESY Zeuthen, Zeuthen, Germany

Funding: Work supported by the BMBF (05K13PEC).
Coherent ultrashort THz pulses induced by a laser-electron interaction are routinely produced and observed at DELTA, a 1.5-GeV synchrotron light source operated by the TU Dortmund University. The turn-by-turn evolution of the radiation spectrum is known to shift to the sub-THz regime after the initial laser-electron interaction. Recently, an ultrafast YBCO-based THz detector has been permanently installed and a Schottky diode has been tested at the THz beamline. Measurements with these detectors showing the temporal evolution of the coherent signals after several revolutions are presented. Furthermore, the concept of a recently designed Fourier-transform spectrometer optimized for the sub-THz region is shown.

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MOPHA037

Visible Light Diagnostics at the ANKA Storage Ring

photon, diagnostics, detector, radiation

866

B. Kehrer, A. Borysenko, E. Hertle, N. Hiller, M. Holz, A.-S. Müller, P. Schönfeldt, P. Schütze
KIT, Karlsruhe, Germany

Synchrotron radiation in the visible light range is a versatile diagnostics tool for accelerator studies. At the ANKA storage ring of the Karlsruhe Institute of Technology (KIT), we have a dedicated visible light diagnostics beamline and two additional beam ports close to the radiation's source point. The visible light diagnostics beamline hosts a time-correlated single-photon-counting unit to measure the bunch filling pattern and a streak camera for longitudinal diagnostics. Recently, the beamline has been extended with a fast-gated intensified camera to study transverse instabilities. The synchrotron light monitor ports were previously used for direct source imaging. Due to the diffraction limit the vertical beam size could not be resolved. One of the two ports has recently been equipped with a double-slit to allow for interferometric measurements of the vertical beam size. In this paper we give an overview of the different setup modifications and present first results.

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MOPHA039

A Fast Gated Intensified Camera Setup for Transversal Beam Diagnostics at the ANKA Storage Ring

storage-ring, radiation, experiment, bunching

872

P. Schütze, A. Borysenko, E. Hertle, N. Hiller, B. Kehrer, A.-S. Müller, P. Schönfeldt
KIT, Karlsruhe, Germany

ANKA, the synchrotron light source at Karlsruhe Institute of Technology (KIT), can be operated in different modes including the short bunch operation with bunch lengths compressed to a few picoseconds. In this mode, coherent synchrotron radiation (CSR) is emitted leading to beam instabilities. For gaining further insight into those processes, a setup based on a fast gated intensified camera was installed recently at the visible light diagnostics beamline of the ANKA storage ring. The experimental layout consists of an optical setup, which magnifies the image of the beam in the horizontal and demagnifies it in the vertical plane to obtain a projection of the horizontal beam shape, the camera itself and a fast scanning galvanometric mirror that sweeps this image across the sensor. This allows the tracking of the horizontal bunch size and position over many turns. In this paper we present the setup and show first measurement results.

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MOPHA042

Online Studies of THz-radiation in the Bursting Regime at ANKA

radiation, optics, synchrotron-radiation, bunching

882

M. Brosi, C.M. Caselle, E. Hertle, N. Hiller, A. Kopmann, A.-S. Müller, M. Schwarz, P. Schönfeldt, J.L. Steinmann, M. Weber
KIT, Eggenstein-Leopoldshafen, Germany

Funding: This work has been supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320
The ANKA storage ring of the Karlsruhe Institute of Technology (KIT) operates in the energy range from 0.5 to 2.5 GeV and generates brilliant coherent synchrotron radiation in the THz range with a dedicated bunch length reducing optic. The producing of radiation in the so-called THz-gap is challenging, but this intense THz radiation is very attractive for certain user experiments. The high degree of compression in this so-called low-alpha optics leads to a complex longitudinal dynamics of the electron bunches. The resulting micro-bunching instability leads to time dependent fluctuations and strong bursts in the radiated THz power. The study of these fluctuations in the emitted THz radiation provides insight into the longitudinal beam dynamics. Fast THz detectors combined with KAPTURE, the dedicated KArlsruhe Pulstaking and Ultrafast Readout Electronics system developed at KIT, allow the simultaneous measurement of the radiated THz intensity for each bunch individually in a multi-bunch environment. This contribution gives an overview of the first experience gained using this setup as an online diagnostics tool.

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MOPHA043

Properties of Transition- and Synchrotron Radiation at FLUTE

radiation, synchrotron-radiation, electron, detector

885

M. Schwarz, A.-S. Müller
KIT, Karlsruhe, Germany
M.T. Schmelling
MPI-K, Heidelberg, Germany

FLUTE (Ferninfrarot Linac Und Test Experiment) is a 41 MeV linear accelerator currently under construction at KIT. It is aimed at accelerator physics and THz radiation research. For this reason the machine will cover a wide range of bunch charges (1 pC up to 3 nC) and lengths (1 fs to 300 fs). One aim of FLUTE is the study of different mechanisms for the generation of intense THz pulses, such as transition- (TR) or synchrotron radiation (SR). In this contribution, we calculate and compare various pulse properties, such as spectra, and electric fields, for both TR and SR.

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MOPHA058

Beam Based Gain Calibration for Beam Position Monitor at J-PARC Main Ring

simulation, operation, proton, closed-orbit

927

H. Kuboki, J. Takano, M. Tejima, T. Toyama
KEK, Ibaraki, Japan
S. Hatakeyama
JAEA/J-PARC, Tokai-mura, Japan

Funding: MEXT KAKENHI Grant Number 25105002, Grant-in-Aid for Scientific Research on Innovative Areas titled "Unification and Development of the Neutrino Science Frontier"
Beam Position Monitor (BPM) is one of the essential elements in a synchrotron facility. It provides the accurate beam positions, which are used to correct the closed orbit distortion. Each BPM is installed with the electronics which enable to acquire the data of the turn-by-turn beam positions. Here, we define the "gain" as the proportionality coefficient between the signal detected at the ADC and the ideal signal without any errors. The signal strength from a BPM electrode varies depending on 1) transmission characteristics of a long cable, 2) processing circuit, and 3) contact resistance at the connected parts. These are the origin of the gain deviations. In order to correct the deviations, a Beam Based Gain Calibration (BBGC) method has been proposed *. Development of a new method for adequate gain calibration is required because any calibration method for routine operation has not been established for BPMs with diagonal-cut electrodes used at J-PARC Main Ring. The results of analysis will be presented using the Total Least Square fitting as an adequate method for the BBGC with sufficient accuracy within 0.6% in one standard deviation.
* M. Tejima et al., DIPAC2011 (2011).

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MOPTY001

Development of Wideband BPM for Precise Measurement of Internal Bunch Motion

impedance, coupling, feedback, network

937

K.G. Nakamura
Kyoto University, Kyoto, Japan
Y.H. Chin, T. Koseki, T. Obina, M. Okada, M. Tobiyama, T. Toyama
KEK, Ibaraki, Japan
Y. Shobuda
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

Funding: This work was supported by MEXT KAKENHI Grant Number 25105002, Grant-in-Aid for Scientific Research on Innovative Areas titled “ Unification and　Development of the Neutrino Science Frontier”
To suppress intra-bunch oscillations and to reduce particle losses, the intra-bunch feedback (IBFB) system has been developed in 2014 for the J-PARC Main Ring (MR). A new BPM was also installed to the MR for the IBFB system. This BPM has a sufficient frequency response and position sensitivity(up to 1.5GHz within 15% fluctuation ). However, a better performance may be needed in future for more precise analysis of internal motions (e.g. due to an electron cloud). We report the development of the BPM and precise measurement results of the BPM characteristics. We also report simulation studies of the digital equalizer which helps to reconstructs the beam shape from beam signals.

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MOPTY003

Measurement of Momentum Spread of the Injection Beam with Longitudinal Tomography Method in the J-PARC RCS

linac, injection, acceleration, operation

944

M. Yoshimoto, H. Harada, H. Hotchi, M. Kinsho, P.K. Saha, F. Tamura, M. Yamamoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

In the J-PARC RCS, the beam tuning toward the design output beam power of 1MW were started after the completing of the beam energy and beam current upgrades in the LINAC. One of the important issues to achieve the 1MW beam operation is the optimization of the injection beam from the LINAC. Due to the longitudinal beam tuning in the LINAC, the momentum spread of the injected beam into the RCS was measured with the longitudinal tomography method. Our longitudinal tomography tool had been developed using the simple algorithm with the Convolution Back-Projection (CBP) method for the beam storage mode of the RCS. Accordingly, we improved this tool to expand into the acceleration mode.

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MOPTY019

Precise Position Measurement by Analyzing the Correlation Between Electrodes of a Single Bpm

simulation, pick-up, hardware, impedance

975

Z.C. Chen
SSRF, Shanghai, People's Republic of China
L.W. Lai, Y.B. Leng, Y.B. Yan
SINAP, Shanghai, People's Republic of China

Beam position is one of the most important parameters in a particle accelerator. The more accurate and precise the measurement system is, the more features of the beam dynamics could be revealed. A method called model-independent analysis (MIA) takes advantage of multiple beam position monitors (BPM) on the storage ring to obtain the actual beam positions by removing the random noise of each BPM. Inspired by MIA, the original voltage waveforms obtained from the electrodes of a single BPM can also be decomposed to get the beam position information. This article discusses the results of the experiments and the evaluation of the performance of the BPM at the Shanghai Institute of Applied Physics.

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MOPTY028

Introduction to BINP HLS to Measure Vertical Changes on PAL-XFEL Buildings and Ground

alignment, operation, laser, ground-motion

994

H. J. Choi, K.H. Gil, H.-S. Kang, S.H. Kim, K.W. Seo
PAL, Pohang, Kyungbuk, Republic of Korea

PAL-XFEL is being installed and will be completed by December of 2015 so that users can be supported beginning in 2016. PAL-XFEL equipment should continuously maintain the bunch beam parameter. To this end, PAL-XFEL equipment has to be kept precisely aligned. As a part of the process for installing PAL-XFEL, a surface geodetic network and the installation of a tunnel measurement network inside buildings is in preparation; additionally, the fiducialization of major equipment is underway. After PAL-XFEL equipment is optimized and aligned, if the ground and buildings go through vertical changes during operation, misalignment of equipments will cause errors in the electron beam trajectory, which will lead to changes to the beam parameter. For continuous and systemic measurement of vertical changes in buildings and to monitor ground sinking and uplifting, the BINP Ultrasonic-type Hydrostatic Levelling System (HLS) is to be installed and operated in all sections of PAL-XFEL for linear accelerator, Undulator and beam line. This study will introduce the operation principle, design concept and advantages (self-calibration) of HLS, and will outline its installation plan and operation plan.

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MOPTY030

Capacitive Linear-Cut Beam Position Monitor Design for Ion Synchrotron at KHIMA Project

vacuum, target, operation, proton

998

J.G. Hwang, C.H. Kim, S.H. Nam, S.Y. Noh
KIRAMS/KHIMA, Seoul, Republic of Korea
G. Hahn, W.T. Hwang, T.K. Yang
KIRAMS, Seoul, Republic of Korea
E.-S. Kim
Kyungpook National University, Daegu, Republic of Korea

The KHIMA (Korea Heavy Ion Medical Accelerator) project is launched to construct the carbon and proton beam base ion therapy machine. It, which consists of the injector with RFQ and IH-DTL linacs, medium beam transport line, synchrotron, and high energy beam transport line, will be provided the carbon beam up to 430 MeV/u and proton beam up to 230 MeV for cancer therapy. The high precision beam position monitor is required to match and control the beam trajectory for the beam injection and closed orbit in synchrotron. It was also used for measuring the beta-function, tune, and chromaticity. Since the bunch length at heavy ion synchrotron is relatively long, a few meters, a box-like device with long plates of typically 20 cm is used to enhance the signal strength and to get a precise linear dependence with respect to the beam displacement. In this presentation, we show the electromagnetic design of the electrode and surroundings to satisfy the resolution of 100 um, the criteria for mechanical aspect to satisfy the position accuracy of 200 um, the measurement result of position accuracy by using the wire test-bench, and the beam-test results with long (~ 1.6 us) electron beam in PAL.

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MOPTY042

ALBA LLRF Upgrades to Improve Beam Availability

cavity, LLRF, beam-loading, operation

1022

A. Salom, B. Bravo, J. Marcos, F. Pérez
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

ALBA is a 3GeV synchrotron light source located in Barcelona and operating with users since May 2012. The RF system of the SR is composed of six cavities, each one powered by combining the power of two 80 kW IOTs through a Cavity Combiner (CaCo). At present, there are several RF interlocks per week. The redundancy given by the six cavities makes possible the survival of the beam after one of these trips. In these cases, the cavity has to be recovered with the circulating beam. An autorecovery process has been implemented in the digital LLRF system in order to recover the faulty RF plant after a trip. But these trips also create perturbations to the beam stability. In order to minimize the beam perturbations induced by these RF interlock, an additional feed-forward loop is being implemented. The functionally, main parameters and test results of these new algorithms will be presented.

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MOPTY073

Commissioning of BPM System for TPS Booster Synchrotron

booster, electronics, injection, storage-ring

1106

P.C. Chiu, Y.-S. Cheng, K.T. Hsu, K.H. Hu, C.H. Kuo
NSRRC, Hsinchu, Taiwan

The TPS is a latest generation of high brightness synchrotron light source and ready for commissioning. It consists of a 150 MeV electron linac, a booster synchrotron, a 3 GeV storage ring, and experimental beam lines. The BPM electronics Libera Brilliance⁺ are adopted for booster and storage ring of Taiwan Photon Source (TPS). The provided BPM data is useful for beam commissioning where it can be used to measure beam position, rough beam intensity along the longitudinal position and also for tune measurement. This report summarizes the efforts on BPM measurement and related diagnostic tools during TPS booster commissioning.

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MOPTY074

Preliminary Beam Test of Synchrotron Radiation Monitoring System at Taiwan Photon Source

storage-ring, booster, radiation, synchrotron-radiation

1109

C.Y. Liao, Y.-S. Cheng, J. -Y. Chuang, K.T. Hsu, S.Y. Hsu, H.P. Hsueh, K.H. Hu, C.K. Kuan, C.Y. Wu
NSRRC, Hsinchu, Taiwan

Taiwan Photon Source (TPS) is a third generation 3 GeV synchrotron light facility. The synchrotron radiation from a dipole can be used to observe the beam parameters. The synchrotron radiation monitor (SRM) systems were designed and implemented for the booster synchrotron and storage ring. The SRM for the booster synchrotron can serve to diagnose the energy ramping process. The beam size decreases when the energy increases was observed. In the storage ring, the streak camera was preferred to observe the beam behaviour of the consecutive bunches. The bunch length and longitudinal instability were observed. The preliminary beam test results are summarized in this report.

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MOPTY080

A Multi-band Single Shot Spectrometer for Observation of mm-Wave Bursts at Diamond Light Source

detector, storage-ring, radiation, synchrotron-radiation

1126

A. Finn, P. Karataev
JAI, Egham, Surrey, United Kingdom
G. Rehm
DLS, Oxfordshire, United Kingdom

Micro-bunch instabilities (MBI) have been detected at many light sources across the world. The radiation bursts produced as a result of this instability occur in the millimetre wavelength regime. In order to understand more about the mechanism of MBI and improve the accuracy of simulations, more information is needed about the dynamics and spectral content of the radiation. A single shot spectrometer has therefore been developed to investigate this instability at Diamond Light Source. Due to their low noise, ultra-fast response and excellent sensitivity, Schottky detector diodes are employed. Currently, seven Schottky detectors are in place covering a range of 33-750 GHz. Unlike previous measurements at Diamond, each of the Schottky detectors has been characterised thus allowing the results obtained to be more easily compared to simulations. In this paper, we present the calibration of each Schottky detector in the spectrometer, the first results of tests with beam, as well as future plans for the spectrometer.

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MOPWI002

Bunch Length Measurements using Synchrotron Light Monitor

linac, emittance, injection, dipole

1143

M.M. Ali, M.G. Tiefenback
JLab, Newport News, Virginia, USA

The bunch length is measured at CEBAF using an invasive technique. The technique depends on applying an energy chirp for the electron bunch and imaging it through a dispersive region. The measurements are taken through Arc1 and Arc2 at CEBAF. The fundamental equations, procedure and the latest results are given.

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MOPWI031

Microwave Modeling for Electron Cloud Density Measurements at CesrTA

simulation, resonance, electron, storage-ring

1227

J.P. Sikora, Y. Li
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
S. De Santis
LBNL, Berkeley, California, USA

Funding: This work is supported by the US National Science Foundation PHY-0734867, PHY-1002467, and the US Department of Energy DE-FC02-08ER41538, DE-SC0006505.
The electron cloud (EC) density in accelerator beam-pipe has been measured using resonant microwaves. The resonances are produced by changes in beam-pipe geometry that generate reflections and standing waves, with typical behavior being similar to a section of waveguide with shorted ends. The technique uses fact that the EC density will shift the resonant frequencies. In previous analysis, we have made the simplifying approximation that the standing waves are multiples of a half-wavelength and that the magnitude of the electric field is symmetric about the longitudinal center of the resonance. In this paper we show that some changes in beam-pipe geometry will result in asymmetric electric field magnitudes along the resonant length. When this is combined with an EC density that varies along this length, the magnitude of the frequency shift will be altered. We present our initial attempt to correct for this effect by modeling the existing beam-pipe using CST Microwave Studio(R) to obtain a more realistic electric field distribution. This correction is then applied to data taken with beam at several resonant frequencies. The measurements were made at the Cornell Electron Storage Ring (CESR), which has been reconfigured as a test accelerator (CesrTA) providing electron or positron beams ranging in energy from 2 to 5 GeV.
* http://dx.doi.org/10.1016/j.nima.2014.03.063

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MOPWI035

Characterization of Visible Synchrotron Radiation Polarization at SPEAR3

polarization, radiation, synchrotron-radiation, diagnostics

1240

W.J. Corbett, A.M. Kiss
SLAC, Menlo Park, California, USA
M.J. Boland
The University of Melbourne, Melbourne, Victoria, Australia
C.L. Li
East China University of Science and Technology, Shanghai, People's Republic of China

Schwinger's equations predict the angular- and spectral distribution of synchrotron radiation across a wide band of the electromagnetic spectrum. Using a visible-light diagnostic beam line, it is possible to characterize the electric field polarization state as a function of vertical observation angle and compare with theory. Complications include accounting for - and π-mode transmission factors at mirror surfaces and precise alignment of the polarizing optics with the principle beam axes. The Stokes parameters are measured and beam polarization ellipse reported.

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MOPWI041

Identification of Intra-Bunch Transverse Dynamics for Model Based Wideband Feedback Control at CERN Super Proton Synchrotron

controls, feedback, simulation, proton

1249

O. Turgut, J.E. Dusatko, J.D. Fox, C.H. Rivetta
SLAC, Menlo Park, California, USA
W. Höfle
CERN, Geneva, Switzerland

Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515 and the US LHC Accelerator Research program (LARP).
Multi-input multi-output (MIMO) feedback design techniques can be helpful to stabilize intra-bunch transverse instabilities induced by electron-clouds or transverse mode couplings at the CERN Super Proton Synchrotron (SPS). These MIMO techniques require a reduced order model of intra-bunch dynamics. We estimate a linear reduced order MIMO models for transverse intra-bunch dynamics and use these models to design model based MIMO feedback controllers. The effort is motivated by the plans to increase currents in the SPS as part of the HL-LHC upgrade. Parameters of the reduced order models are estimated based on driven beam SPS measurements. We study different types of controllers. We test the model based designs using macro particle simulation codes (CMAD and HEADTAIL) and compare its performance with FIR filters tested during beam measurements of the feedback system in SPS machine development (MD) studies.

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MOPWI046

eDT and Model-based Configuration of 12 GeV CEBAF

operation, controls, radiation, linac

1259

D.L. Turner
JLab, Newport News, Virginia, USA

Funding: Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
This poster will discuss model-driven setup of CEBAF for the 12GeV era, focusing on the elegant Download Tool (eDT). eDT is a new operator tool that generates magnet design setpoints for various machine energies and pass configurations. eDT was developed in the effort towards a process for reducing machine configuration time and reproducibility by way of an accurate accelerator model.

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MOPWI052

Responsivity Study of Diamond X-ray Monitors with nUNCD Contact

photon, detector, plasma, database

1273

M. Gaowei, J. Smedley
BNL, Upton, Long Island, New York, USA
E.M. Muller, T. Zhou
SBU, Stony Brook, New York, USA
A.V. Sumant
Argonne National Laboratory, Center for Nanoscale Materials, Argonne, USA

Nitrogen doped ultrananocrystalline diamond (nUNCD) grown on the surface of a CVD single crystal diamond is tested at various beamlines covering an x-ray photon energy range of 200eV to 28 keV. The nUNCD has much lower x-ray absorption than metal contacts and is designed to improve the performance of our device. The responsivity of nUNCD diamond x-ray detector is compared with the conventional platinum coated diamond x-ray beam position monitor and the results are presented in this paper.

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TUXC2

Engineering Challenges of Future Light Sources

storage-ring, vacuum, feedback, emittance

1308

R.T. Neuenschwander, L. Liu, S.R. Marques, A.R.D. Rodrigues, R.M. Seraphim
LNLS, Campinas, Brazil

We review some of the present engineering challenges associated with the design and construction of ultra-low emittance storage rings, the 4th generation storage rings (4GSR). The field is experiencing a growing interest since MAX-IV, followed by Sirius, started to build storage rings based on multi-bend-achromat (MBA) lattices. It was the recent progress in accelerator technology that allowed these facilities to base their designs on this kind of lattice. Although the challenges are starting to be overcome, many issues are still open and a lot of R&D is required until the 4GSR achieve optimal performance.

Slides TUXC2 [7.022 MB]

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TUXC3

Commissioning of the Taiwan Photon Source

booster, storage-ring, quadrupole, emittance

1314

C.-C. Kuo, C.-T. Chen, J.Y. Chen, M.-S. Chiu, P.J. Chou, K.T. Hsu, Y.C. Liu, G.-H. Luo, H.-J. Tsai, F.H. Tseng
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source (TPS) is a 3-GeV third-generation synchrotron light source located in Hsinchu, Taiwan. After ground breaking on February 7, 2010 and five years of construction and hardware developments, commissioning of the beam began on December 12, 2014. The booster ring reached the design energy of 3 GeV on December 16. Beam transferred to the storage ring and first accumulation at 3 GeV produced the first synchrotron light on December 31. This report presents results and experience of the TPS commissioning.

Slides TUXC3 [5.425 MB]

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TUAC1

Beam Instrumentation and Diagnostics for High Luminosity LHC

radiation, diagnostics, pick-up, collimation

1349

O.R. Jones, E. Bravin, B. Dehning, T. Lefèvre, H. Schmickler
CERN, Geneva, Switzerland

The extensive array of beam instrumentation with which the LHC is equipped, has played a major role in its commissioning, rapid intensity ramp-up and safe and reliable operation. High Luminosity LHC (HL-LHC) brings with it a number of new challenges in terms of instrumentation that will be discussed in this contribution. The beam loss system will need significant upgrades in order to be able to cope with the demands of HL-LHC, with cryogenic beam loss monitors under investigation for deployment in the new inner triplet magnets to distinguish between primary beam losses and collision debris. Radiation tolerant integrated circuits are also being developed to allow the front-end electronics to sit much closer to the detector. Upgrades to other existing systems are also envisaged; including the beam position measurement system in the interaction regions and the addition of a halo measurement capability to synchrotron light diagnostics. Additionally, several new diagnostic systems are under investigation, such as very high bandwidth pick-ups and a streak camera installation, both able to perform intra-bunch measurements of transverse position on a turn by turn basis.

Slides TUAC1 [4.490 MB]

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TUPWA001

Measurement of the Incoherent Depth of Field Effect on Horizontal Beam Size Using a Synchrotron Light Interferometer

electron, photon, storage-ring, lattice

1391

M.J. Boland
SLSA, Clayton, Australia
W.J. Corbett
SLAC, Menlo Park, California, USA
T.M. Mitsuhashi
KEK, Ibaraki, Japan

The electron beam size as measured using synchrotron light in a circular accelerator is influenced by the incoherent depth of field effect. This effect comes about due to the instantaneous opening angle of the emitted synchrotron radiation (SR) and the acceptance angle of the SR light monitor beamline. Measurements were made using a visible light interferometer at the visible light beamlines in three circular accelerators at ATF, SPEAR3 and AS. The first order spatial coherence of the beam was measured and from that the horizontal beam size was calculated. The data is compared with a theory of synchrotron radiation with and without the horizontal incoherent field depth effect.

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TUPWA004

Operator Roles at the Australian Synchrotron

operation, controls, database, storage-ring

1397

D.C. McGilvery
ASCo, Clayton, Victoria, Australia
G. LeBlanc
SLSA, Clayton, Australia

The Accelerator Operators at the Australian Synchrotron undertake a wide variety of critical functions as part of their regular duties. In addition to normal Control Room duties, they play a major Role in Machine Physics, provide after hours support for Users on Beamlines and contribute extensively to the Controls and Database Development across the facility.

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TUPWA005

Comparison of Bunch Compression Schemes for the AXXS FEL

linac, simulation, FEL, electron

1399

T.K. Charles, D.M. Paganin
Monash University, Faculty of Science, Clayton, Victoria, Australia
A.A. Aksoy
Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
M.J. Boland, R.T. Dowd
SLSA, Clayton, Australia
A. Latina, D. Schulte
CERN, Geneva, Switzerland

Different types of electron bunch compression schemes are compared for the AXXS FEL design study. The main linac for the proposed machine is based on CLIC x-band structures. This choice leaves several options for the bunch compression schemes which impact the injection system RF band. Both harmonic linearization and phase modulation linearization are considered and their relative strengths and weaknesses compared. Simulations were performed to compare the performance of an s-band injector with a higher harmonic RF linearization and an x-band injector. One motivation for the study is to optimise the length of the AXXS machine, allowing the linac to fit onto the proposed and also act as the injector to the existing storage ring at the Australian Synchrotron.

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TUPWA021

A New Method to Generate Ultrashort and Coherent Pulses of Short-Wavelength Synchrotron Radiation

laser, electron, radiation, storage-ring

1448

S. Khan
DELTA, Dortmund, Germany

Funding: Work supported by the BMBF (contract 05K13PE3)
A laser-based method to generate ultrashort pulses of synchrotron radiation in electron storage rings is coherent harmonic generation (CHG) using two undulators to produce coherent radiation at harmonics of the initial laser wavelength by microbunching. The bunching factor and thus the pulse intensity, however, decreases exponentially with increasing harmonic order. Echo-enabled harmonic generation (EEHG), proposed in 2009 as FEL seeding scheme*, can be used to produce short synchrotron radiation pulses at higher harmonics, but requires three undulators in a straight section. In this paper, a less space-consuming method based on seeding with intensity-modulated laser pulses is introduced, which also has the potential of significant bunching factors at high harmonics.
* G. Stupakov, PRL 102 (2009), 074801.

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TUPWA022

Characterization and Optimization of Ultrashort and Coherent VUV Pulses at the DELTA Storage Ring

laser, electron, radiation, undulator

1452

S. Khan, F.H. Bahnsen, M. Bolsinger, S. Hilbrich, M. Huck, M. Höner, C. Mai, A. Meyer auf der Heide, R. Molo, H. Rast, G. Shayeganrad, P. Ungelenk
DELTA, Dortmund, Germany
H. Huck
DESY Zeuthen, Zeuthen, Germany

Funding: Work supported by BMBF (05K13PE3 and 05K13PEC), DFG (INST 212/236-1 FUGG) and the Land NRW
At DELTA, a 1.5-GeV synchrotron light source operated by the TU Dortmund University, a source for coherent and ultrashort vacuum-ultraviolet (VUV) and terahertz (THz) pulses is now in operation. The VUV source is based on a laser-induced energy modulation and coherent harmonic generation (CHG). A subsequently developing dip in the longitudinal electron distribution gives rise to coherent THz radiation. Recent results regarding the optimization of the laser-electron interaction and characterization of the CHG pulses are presented.

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TUPWA025

Beam Heat Load Analysis with COLDDIAG: A Cold Vacuum Chamber for Diagnostics

electron, storage-ring, diagnostics, vacuum

1459

R. Voutta, S. Casalbuoni, S. Gerstl, A.W. Grau, T. Holubek, D. Saez de Jauregui
KIT, Eggenstein-Leopoldshafen, Germany
R. Bartolini, M.P. Cox, E.C. Longhi, G. Rehm, J.C. Schouten, R.P. Walker
DLS, Oxfordshire, United Kingdom
M. Migliorati, B. Spataro
INFN/LNF, Frascati (Roma), Italy

The knowledge of the heat intake from the electron beam is essential to design the cryogenic layout of superconducting insertion devices. With the aim of measuring the beam heat load to a cold bore and understanding the responsible mechanisms, a cold vacuum chamber for diagnostics (COLDDIAG) has been built. The instrumentation comprises temperature sensors, pressure gauges, mass spectrometers and retarding field analyzers, which allow to study the beam heat load and the influence of the cryosorbed gas layer. COLDDIAG was installed in the storage ring of the Diamond Light Source from September 2012 to August 2013. During this time measurements were performed for a wide range of machine conditions, employing the various measuring capabilities of the device. Here we report on the analysis of the measured beam heat load, pressure and gas content, as well as the low energy charged particle flux and spectrum as a function of the electron beam parameters.

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TUPWA028

Simulation Results of the Beam Transport of Ultra-Short Electron Bunches in Existing Beam Transfer Lines to Sinbad

linac, optics, gun, electron

1466

U. Dorda, R.W. Aßmann, K. Flöttmann, B. Marchetti, Y.C. Nie, J. Zhu
DESY, Hamburg, Germany

SINBAD, the upcoming accelerator R&D facility at DESY, will host multiple independent experiments on the production and acceleration of ultra-short bunches including plasma wakefield experiments. As a possible later upgrade the option to transport higher energy electrons (up to 800 MeV) or positrons (up to 400 MeV) from the existing DESY Linac 2 to the facility is studied. Though existing a possible connection using e.g. a part of the DESY synchrotron as a transfer line and other currently unused transfer-line, these machines were not designed for the desired longitudinal bunch compression and high peak current required by e.g. beam driven plasma wake-field experiments. Simulation results illustrate the modifications to the current layout that would have to be implemented and the corresponding achievable beam parameters are given.

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TUPWA034

Status of the Recommissioning of the Synchrotron Light Source PETRA III

emittance, lattice, operation, optics

1485

R. Wanzenberg, M. Bieler, M. Ebert, L. Fröhlich, J. Keil, J. Klute, G. Kube, G.K. Sahoo
DESY, Hamburg, Germany

At DESY the Synchrotron Light Source PETRA III has been extended in the North and East section of the storage ring to accommodate ten additional beam lines. The PETRA ring was converted into a dedicated synchrotron light source from 2007 to 2009. Regular user operation started in summer 2010 with a very low emittance of 1 nm at a beam energy of 6 GeV and a total beam current of 100 mA. All photon beamlines were installed in one octant of the storage ring. Nine straight sections facilitated the installation of insertion devices for 14 beam lines. Due to the high demand for additional beamlines the lattice of the ring was redesigned to accommodate 10 additional beamlines in the future. In a one year long shut-down two new experimental halls were built. The recommissioning of PETRA III started in February 2015. We are reporting the current status of synchrotron light source including the performance of the subsystems.

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TUPWA043

Non-interferometric Spectral Analysis of Synchrotron Radiation in the THz regime at ANKA

radiation, synchrotron-radiation, electron, storage-ring

1509

J.L. Steinmann, M. Brosi, E. Bründermann, C.M. Caselle, E. Hertle, N. Hiller, B. Kehrer, A.-S. Müller, M. Schuh, M. Schwarz, P. Schönfeldt, P. Schütze
KIT, Karlsruhe, Germany
J.L. Hesler
Virginia Diodes Inc., Charlottesville, USA

Interferometry is the quasi-standard for spectral measurements in the THz- and IR-range. The frequency resolution, however, is limited by the travel range of the interferometer mirrors. Therefore, a resolution in the low megahertz range would require interferometer arms of about 100 m. As an alternative, heterodyne measurements provide a resolution in the Hertz range, an improvement of 6 orders of magnitude. Here we present measurements done at ANKA with a VDI WR3.4SAX, a mixer that can be tuned to frequencies from 220 GHz to 330 GHz and we show how the bunch filling pattern influences the amplitude of specific frequencies.

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TUPJE005

Development of Pulsed Multipole Magnet for Aichi SR Storage Ring

storage-ring, electron, injection, multipole

1616

K. Ito, M. Hosaka, A. Mano, T. Takano, Y. Takashima
Nagoya University, Nagoya, Japan
K. Hayashi, M. Katoh
UVSOR, Okazaki, Japan
N. Yamamoto
KEK, Ibaraki, Japan

The Aichi synchrotron radiation (Aichi SR) center is an industrial oriented synchrotron light source facility. The electron energy and circumference of the storage ring are 1.2 GeV and 72 m. The natural emittance is 53 nm-rad. Since the pulsed multipole injection scheme provides great advantages for relatively smaller SR rings*, we are developing a pulsed multipole injection system for Aichi SR storage ring. In this system, it is essential to minimize the perturbation to the stored beam. To realize the required performances, we have to minimize the residual field at stored beam position, taken into account the field generated by the copper current lead of the input terminal. In addition, we carried out the analytical calculation to estimate the magnet field due to the current lead and optimized the geometrical structure of them. Construction of the multipole magnet will be completed in March 2015 and the field measurement will be carried out in April. In this presentation, we report the detail of the magnet design and the measurement results of pulsed magnetic field for the manufactured magnet.
* N. Yamamoto, et. al., NIM A 767, 26-33 (2014)

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TUPJE006

Recent Developments of UVSOR-III

undulator, injection, laser, operation

1619

M. Katoh, K. Hayashi, J. Yamazaki
UVSOR, Okazaki, Japan
M. Adachi, T. Konomi, N. Yamamoto
KEK, Ibaraki, Japan
M. Hosaka, Y. Takashima
Nagoya University, Nagoya, Japan

A 750 MeV low energy synchrotron light source, UVSOR, has been operational since 1983. About ten years after the first major upgrade in 2003, the second major upgrade was carried out in 2012, in which all the bending magnets were replaced with combined function ones and a new in-vacuum undulator was installed in the last straight section reserved for undulators. After this upgrade, the light source, UVSOR-III, has been operational with small emittance of 17 nm-rad, with six undulators, and fully with the top-up injection at 300mA. Adding to the present status of the accelerator, most recent progresses in the pulsed sextupole magnet for the beam injection and in the coherent light source development station will be presented.

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TUPJE012

Preliminary Result of Photon Counting Acquisition Scheme for Laser Pump/X-ray Probe Experiments

laser, experiment, detector, timing

1638

J. He, J.S. Cao, G. Gao, Y.F. Sui, Y. Tao, J.H. Yue, Z. Zhang, Y.F. Zhou
IHEP, Beijing, People's Republic of China

Funding: This work is supported by the NSFC under grant No.11305186
R&D project has been initiated for a proposed ultralow emittance (~50pm.rad) synchrotron light source built in Beijing. The R&D includes the development of high repetition rate laser pump/X-ray probe for ultrafast dynamics detection in future source. In a typical laser pump/X-ray probe measurement, the X-ray pulse follows a laser pulse in adjustable delay. We are interested in the difference between laser on and laser off at different delay, which will snapshot dynamic process. To capture this trivial difference, it requires the acquisition system to single out the signal from this special X-ray pulse at adequate S/N ratio. For the R&D of high repetition rate pump-probe, we have set up a prototype counting acquisition system based on NIM modular electronics, which was tested in Beijing Synchrotron Radiation Facility (BSRF). The laser will be synchronized with a camshaft bunch at 124 kHz, a tenth of the revolution frequency. Avalanche Photo Diode (APD) was used to detect the X-ray pulse from this camshaft bunch due to its nanosecond response. Before the laser is delivered, we mimic the 124 kHz laser- on signal. The signals from APD are separated by power dividers into two Constant Fraction Discriminator (CFD) input channels. The signal in laser-on/off channel is gated out at 1.24MHz using the 1.24MHz timing signal divided from 499.8 MHz RF signal, while the mimic laser-on signal gated out at 124 kHz. Multiplied by ten times, the mimic laser-on signal counts should be consistent with the laser-on+off counts, if our counting modular works well. We carried out this test at 1W1B wiggler beam line to measure the Fe fluorescence signal. The performance of our system is demonstrated in the good consistency between mimic laser on and laser on+off signals.

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TUPJE016

COHERENT SYNCHROTRON RADIATION FIELD AND THE ENERGY LOSS IN A WAVY BEAM

electron, radiation, wakefield, synchrotron-radiation

1650

D.R. Xu, H. Xu
USTC/NSRL, Hefei, Anhui, People's Republic of China

The synchrotron radiation will be coherent when the wavelength of the radiation can be compared with the bunch length. There are two approaches to produce Coherent Synchrotron Radiation (CSR) on a storage ring. One is to compress the bunch length, the other one is to produce a wavy beam which has high spatial repetition along the longitudinal direction. The latter one can expand the radiation frequency range of a light source. However, CSR can bring nonlinear effect which brings in extra instability. The Lienard-Wiechert potentials in three-dimensional space may have very complicated forms. The most common way to investigate CSR is numerical method. This paper try to use a simple model to obtain energy loss of the electrons in theory.

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TUPJE018

On-axis Injection Scheme for Ultimate Storage Ring with Double RF Systems

injection, emittance, storage-ring, radiation

1657

B.C. Jiang, S.Q. Tian, M.Z. Zhang, Q.L. Zhang, Z.T. Zhentang
SINAP, Shanghai, People's Republic of China

An on-axis injection scheme using double RF systems for an ultimate storage ring which holds very small dynamic aperture is proposed. By altering RF voltages, empty RF buckets can be created which will be used for on-axis injection. After bunches are injected, a reverse voltage altering process is performed and the injected bunches can be longitudinally dumped to the main buckets.

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TUPJE035

Optimization of Turn-by-Turn Measurements at Soleil and Alba Light Sources

quadrupole, lattice, betatron, storage-ring

1686

M. Carlà, G. Benedetti, Z. Martí
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
L.S. Nadolski
SOLEIL, Gif-sur-Yvette, France

Turn-by-turn measurements paves the way for fast storage ring diagnostics. On the other hand turn-by-turn technique is by its very nature delicate, requiring an extensive system tuning and understanding. During last year several attempts to recover linear model informations from turn-by-turn measurements has been carried out in cooperation between the synchrotrons of SOLEIL and ALBA. A routine to extract phase advance and betatron amplitude from turn-by-turn measurements in presence of damping has been developed. Moreover a procedure to retrieve quadrupole errors from such observables has been developed tested and verified against the traditional diagnostics tools based on closed orbit measurements. A comparison between the different methods and the performance of the two different experimental setups are reported.

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TUPJE036

A New Bench Concept for Measuring Magnetic Fields of Big Closed Structures

controls, operation, vacuum, alignment

1690

J. Campmany, F. Becheri, C. Colldelram, J. Marcos, V. Massana, J. Nicolás, L. Ribó
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

The measurement of big closed magnetic structures is becoming a challenge of great interest. The main reason is the tendency towards building accelerators with high magnetic fields produced by small gap magnets, as well as the development of cryogenic or superconducting narrow-gap insertion devices. Usual approach, based on side-measurements made with a Hall probe mounted on the tip of a motorized arm based on a long granite bench is no more applicable to such closed structures. So, new concepts and approaches have been developed, mainly based on complex devices that insert a Hall probe inside the magnetic structure maintaining the desired position by close-loop controls. The main problem of these devices is that they are not general-purpose oriented: they need a special vacuum chamber, require a specific geometry of the magnetic structure, or does not provide 3D field-map measurements. We present in this paper a new bench that has been built at ALBA synchrotron that is simple, multi-purpose and can be a general solution for measuring big closed structures.

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TUPJE053

Hardware Improvements and Beam Commissioning of the Booster Ring in Taiwan Photon Source

booster, hardware, linac, injection

1741

H.-J. Tsai, C.-T. Chen, J.Y. Chen, M.-S. Chiu, P.C. Chiu, P.J. Chou, K.T. Hsu, K.H. Hu, C.-C. Kuo, Y.-C. Liu, G.-H. Luo, F.H. Tseng
NSRRC, Hsinchu, Taiwan

Taiwan Photon Source (TPS), a low emittance 3-GeV third-generation synchrotron light source, began its hardware integration testing, safety checkout and beam commissioning on August 12, 2014 [1]. The booster ring and the storage ring share the same tunnel in a concentric fashion; the booster ring has circumference 496.8 m, the largest among light source facilities in operation. A combined-function FODO lattice is adopted for the booster ring with natural emittance 10 nm-rad. After hardware improvements were completed, the commissioning of the beam in the booster ring began on December 12 and attained the 3-GeV design energy on December 16.

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TUPJE057

Realistic Undulators for Intense Gamma-ray Beams at Future Colliders

undulator, electron, positron, simulation

1756

A.O. Alrashdi, I.R. Bailey
Lancaster University, Lancaster, United Kingdom
D. Newton
The University of Liverpool, Liverpool, United Kingdom

The baseline designs for the ILC and CLIC require the production of an intense flux of gamma rays in their positron sources. In the case of CLIC the gamma rays are produced by a Compton backscattering source, but in this paper we concentrate on undulator-based sources as proposed for the ILC. We present the development of a simulation to generate a magnetic field map based on a Fourier analysis of any measured field map. We have used a field map measured from the ILC helical undulator prototype to calculate the typical distribution of field errors, and used them in our calculations to produce simulated field maps. We show that a loss of gamma ray intensity of ~ 8% could be expected, compared to the ideal case. This leads to a similar drop in positron production which can be compensated for by increasing the undulator length.

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TUPMA035

Control of Synchrotron Radiation Effects during Recirculation

emittance, controls, recirculation, lattice

1913

D. Douglas, S.V. Benson, A.S. Hofler, R. Kazimi, R. Li, Y. Roblin, C. Tennant
JLab, Newport News, Virginia, USA
G.A. Krafft, B. Terzić
ODU, Norfolk, Virginia, USA
C.-Y. Tsai
Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA

Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177.
Numerous proposals invoke recirculation and/or energy recovery for cost-performance optimization. These often encounter challenges with the beam-quality-degrading effects of incoherent and coherent synchrotron radiation (ISR and CSR). We describe a means of controlling of this degradation. The approach utilizes results by diMitri et al. *, and invokes behavior observed during simulations of the recirculation process. The method is based on the use of periodically isochronous 2nd-order achromats; this not only insures that the conditions for the suppression of CSR-driven emittance growth are met*, it also suppresses micro-bunching gain over a broad range of parameter space **. Details of specific designs will be presented, and a reference to an analysis of micro-bunching effects ** provided. A planned test of the CSR suppression mechanism in CEBAF will be described.
*S. diMitri et al., Phys. Rev. Lett. 110, 014801, 2 January 2013.
**C.Y. Tsai et al., these proceedings.

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TUPMA057

Commissioning of Active Interlock System for NSLS II Storage Ring

storage-ring, radiation, synchrotron-radiation, photon

1962

S. Seletskiy, C. Amundsen, J. Choi, J.H. De Long, K.M. Ha, C. Hetzel, H.-C. Hseuh, Y. Hu, P. Ilinski, S.L. Kramer, Y. Li, M.A. Maggipinto, J. Mead, D. Padrazo, T.V. Shaftan, G. Shen, O. Singh, R.M. Smith, W.H. Wahl, G.M. Wang, F.J. Willeke, L. Yang
BNL, Upton, Long Island, New York, USA

The NSLS-II storage ring is protected from possible damage from insertion devices (IDs) synchrotron radiation by a dedicated active interlock system (AIS). It monitors electron beam position and angle and triggers beam drop if beam orbit exceeds the boundaries of pre-calculated active interlock envelope. In this paper we describe functional details of the AIS and discuss our experience with commissioning of the AIS for the first six IDs installed in the storage ring.

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TUPTY031

Tools for Flexible Optimisation of IR Designs with Application to FCC

radiation, synchrotron-radiation, simulation, detector

2072

H. Burkhardt
CERN, Geneva, Switzerland
M. Boscolo
INFN/LNF, Frascati (Roma), Italy

The interaction regions of future high-luminosity colliders require well balanced designs, which provide both for a very high luminosity and at the same time keep backgrounds and radiation at tolerable levels. We describe a set of flexible tools, targeted at providing a first evaluation of losses in the interaction region as part of the design studies, and their application to FCC.

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TUPTY058

Mitigating Performance Limitations of Single Beam-pipe Circular e⁺e⁻ Colliders

luminosity, collider, electron, operation

2160

M. Koratzinos
DPNC, Genève, Switzerland
F. Zimmermann
CERN, Geneva, Switzerland

Renewed interest in circular e⁺e⁻ colliders has spurred designs of single beam-pipe machines, like the CEPC in China, and double beam pipe ones, such as the FCC-ee effort at CERN. Single beam-pipe designs profit from lower costs but are limited by the number of bunches that can be accommodated in the machine. We analyse these performance limitations and propose a solution that can accommodate O(1000) bunches while keeping more than 90% of the ring with a single beam pipe.

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TUPTY060

The FCC-ee Study: Progress and Challenges

collider, interaction-region, radiation, optics

2165

M. Koratzinos
DPNC, Genève, Switzerland
S. Aumon, C. Cook, A. Doblhammer, B. Härer, B.J. Holzer, R. Tomás, F. Zimmermann
CERN, Geneva, Switzerland
A.V. Bogomyagkov, E.B. Levichev, D.N. Shatilov
BINP SB RAS, Novosibirsk, Russia
M. Boscolo
INFN/LNF, Frascati (Roma), Italy
L.E. Medina Medrano
UGTO, Leon, Mexico
U. Wienands
SLAC, Menlo Park, California, USA

The FCC (future circular collider) study represents a vision for the next large project in high energy physics, comprising a 80-100 km tunnel that can house a future 100TeV hadron collider. The study also includes a high luminosity e⁺e⁻ collider operating in the centre-of-mass energy range of 90-350 GeV as a possible intermediate step, the FCC-ee. The FCC-ee aims at definitive electro-weak precision measurements of the Z, W, H and top particles, and search for rare phenomena. Although FCC-ee is based on known technology, the goal performance in luminosity and energy calibration make it quite challenging. During 2014 the study went through an exploration phase and during the next three years a conceptual design report will be prepared.

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TUPTY077

Strong-Strong Beam-Beam Simulation of Bunch Length Splitting at the LHC

simulation, emittance, resonance, beam-beam-effects

2210

J. Qiang, S. Paret
LBNL, Berkeley, California, USA
K. Ohmi
KEK, Ibaraki, Japan
T. Pieloni
CERN, Geneva, Switzerland

Longitudinal bunch length splitting was observed for some LHC beams. In this paper, we will report on the study of the observation using strong-strong beam-beam simulations. We explore a variety of factors including initial momentum deviation, collision crossing angle, synchroton tune, chromaticity, working points and bunch intensity that contribute to the beam particle loss and the bunch length splitting, and try to understand the underlying mechanism of the observed phenomena.

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WEXC3

Improving the Energy Efficiency of Accelerator Facilities

klystron, radiation, operation, neutron

2428

M. Seidel
PSI, Villigen PSI, Switzerland
R. Gehring
KIT, Karlsruhe, Germany
E. Jensen
CERN, Geneva, Switzerland
T.I. Parker
ESS, Lund, Sweden
P.J. Spiller, J. Stadlmann
GSI, Darmstadt, Germany

New particle accelerator based research facilities tend to be much more productive, but often in coincidence with much higher energy consumption. The total energy consumption of mankind is steeply rising, while some European countries decided to terminate nuclear power generation and to switch to renewable energy production. Also the CO2 problem gives rise to new approaches for energy production and in all strategies the efficiency of utilization of electrical energy plays an important role. For the public acceptance of particle accelerator projects it is thus very important to optimize them for best utilization of electrical energy and to show these efforts to funding bodies and to the public. Within the European accelerator development program Eucard-2 we organise a network EnEfficient that aims at improving the energy efficiency of accelerators. In this paper we give some background information on the political situation, we describe the power flow in accelerator facilities and we give examples for developments of efficient accelerator systems, such as magnets, RF generation and beam acceleration, heat recovery and energy management.

Slides WEXC3 [2.611 MB]

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WEBD1

12 GeV CEBAF Transverse Emittance Evolution

emittance, optics, operation, linac

640

T. Satogata, Y. Roblin, M.G. Tiefenback, D.L. Turner
JLab, Newport News, Virginia, USA

We present commissioning results of measurements of beam phase space evolution of the newly commissioned 12 GeV CEBAF accelerator. These measurements range over two orders of magnitude in energy for a non-equilibrium beam, from near the photocathode to the diamond bremsstrahlung target for the GlueX experiment. We also compare these measurements to modeled beam evolution, and emittance growth expectations driven by synchrotron radiation.

Slides WEBD1 [4.297 MB]

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WEBD2

Survey of Commissioning of Recent Storage Ring Light Sources

survey, factory, vacuum, lattice

2482

M. Borland
ANL, Argonne, Ilinois, USA
R. Bartolini, I.P.S. Martin
DLS, Oxfordshire, United Kingdom
L.O. Dallin
CLS, Saskatoon, Saskatchewan, Canada
P. Kuske, R. Müller
HZB, Berlin, Germany
L.S. Nadolski
SOLEIL, Gif-sur-Yvette, France
F. Pérez
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
J.A. Safranek
SLAC, Menlo Park, California, USA
S. Shin
PAL, Pohang, Kyungbuk, Republic of Korea
Z.T. Zhentang
SINAP, Shanghai, People's Republic of China

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source and other existing storage ring light sources are contemplating replacing an existing, operating storage ring with a multi-bend achromat lattice. One issue is that existing light sources have large user communities who are greatly inconvenienced by extended shutdowns. Hence, there will be a premium placed on rapid commissioning of the new lattice. To better understand the possibilities, we undertook a survey of recent commissioning experience at third-generation light sources. We present a summary of that survey here.

Slides WEBD2 [0.173 MB]

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WEPMA002

The Beam Chopper Power Converter for MedAustron: Safety by Design and Development

hardware, kicker, controls, software

2741

T. Stadlbauer, R. Filippini, X. German, F. Osmić, P. Urschütz
EBG MedAustron, Wr. Neustadt, Austria
M.J. Barnes, T. Kramer
CERN, Geneva, Switzerland
M. Beerwald, D. Dirksen
Poynting GmbH, Dortmund, Germany

MedAustron is the Austrian centre for hadron therapy and non-clinical research. The beam chopper system is an essential component for patient safety in specific hazardous situations as well as for beam delivery from the synchrotron to the irradiation rooms. This paper presents the results from the development phase and the commissioning of the MedAustron beam chopper system. Details will be given on the design, the risk management, the test and the verification of the chopper power converter (PKC).

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WEPMA003

Vacuum System Design for the Sirius Storage Ring

vacuum, radiation, storage-ring, dipole

2744

R.M. Seraphim, O.R. Bagnato, R.O. Ferraz, H.G. Filho, G.R. Gomes, M. Nardin, R.F. Oliveira, B.M. Ramos, A.R.D. Rodrigues, M.B. Silva, T.M. da Rocha
LNLS, Campinas, Brazil

Sirius is a 3 GeV 4th-generation light source under construction by the Brazilian Synchrotron Light Laboratory (LNLS). Sirius will have a low emittance storage ring, 0.28 nm-rad, based on 20 cells of a highly compact lattice – 5-bend achromat (5BA). This lattice concept leaves very little space for components and therefore requires narrow vacuum chambers with tight mechanical tolerances. Most of the storage ring vacuum chambers will be made of OFS copper and have a circular cross section with inner diameter of 24 mm and a wall thickness of 1 mm. The unused synchrotron radiation will be distributed along the water cooled walls of the chambers. Due to the small conductance of the chambers, the vacuum pumping will be based on distributed concept and then non-evaporable getter (NEG) coating will be extensively used, with more than 95% of the chambers being coated. In this paper, we present an overview of the storage ring vacuum system and the main vacuum chambers fabrication developments.

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WEPMA015

Water-cooled Thin Walled Beam Pipes of the Fast Ramping Storage Ring ELSA

radiation, electron, dipole, synchrotron-radiation

2780

P. Hänisch, W. Hillert, B. Neff
ELSA, Bonn, Germany

At the Electron Stretcher Facility ELSA of Bonn University thin walled beam pipes are in use to reduce eddy current loss to a minimum. The operation of the accelerator places high demands on the beam pipes like static stress because of the inner vacuum and additional one-sided thermal stress caused by synchrotron radiation. A first generation of thin walled beam pipes had been developed and manufactured during the construction of the stretcher ring in 1985. These pipes were successfully in operating stage the following ten years. The beam pipes had a wall thickness of 0.3mm, a length of 3m, and a bending radius of ca. 10.5m. Special pipes with a sideway branch for synchrotron radiation experiments have been manufactured in the same assembly dimension. In the course of an intensity upgrade, a second generation of beam pipes has been developed in 1995. To reduce the thermal stress caused by the synchrotron radiation an internal water cooling was mounted. In this contribution the design and manufacturing principles of the thin walled beam pipes with water cooling are presented.

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WEPMA016

A New RF station for the ELSA Stretcher Ring

klystron, cavity, LLRF, electron

2783

M. Schedler, A. Dieckmann, P. Hänisch, W. Hillert
ELSA, Bonn, Germany

At the Electron Stretcher Facility ELSA of Bonn University, an increase of the maximum stored beam current from 20 mA to 200 mA is planned. The storage ring operates applying a fast energy ramp of 6 GeV/s from 1.2 GeV to 3.2 GeV and afterwards a slow extraction over a few seconds to the hadron physics experiments. The beam current is mainly limited due to missing RF power at highest energies in order to compensate for synchrotron radiation losses. The current stretcher ring's RF station is based on a single 200 kW klystron driving two 5-cell PETRA type cavities. To achieve the desired beam current at maximum energy two additional 7-cell PETRA type cavities, drivin by a second klystron, will be installed. With this upgrade, sufficient beam lifetime for slow beam extraction will be provided and thus ensure an adequate duty cycle of the external beam current. The general setup of the new RF station as well as the changes in operation when switching from one to two stations will be presented.

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WEPMA020

SIS100 Dipole Field Harmonics and Dynamic Aperture Calculations

dipole, multipole, quadrupole, simulation

2795

C. Omet, E.S. Fischer, G. Franchetti, V. Kornilov, A. Mierau, C. Roux, P. Schnizer, D. Schäfer, S. Sorge, P.J. Spiller, K. Sugita
GSI, Darmstadt, Germany

During the acceptance test of the First of Series (FoS) SIS100 super-ferric dipole, detailed field measurements have been done. The harmonic coefficients have been extracted from these and dynamic aperture simulations have been done which are presented here. Furthermore, geometric precision measurement tools for the magnet have been developed to track down the field errors to geometric errors. Finally, mitigation actions have been taken to reduce these errors during manufacturing to ensure the design beam survival rate in SIS100.

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WEPMA024

System Design for a Deterministic Bunch-to-Bucket Transfer

simulation, LLRF, ion, timing

2809

T. Ferrand
TEMF, TU Darmstadt, Darmstadt, Germany
J.N. Bai
IAP, Frankfurt am Main, Germany

Funding: Supported by GSI and the Technical University Darmstadt in the frame of the cooperation for FAIR.
A deterministic bunch to bucket transfer system is currently under development in the frame of the FAIR project at GSI. To achieve our accuracy and stability requirements, a set of hardware modules will be implemented. These hardware modules are expected to provide values such as the relative phase advance between the RF systems of both, the source and the target synchrotron according to an external timing system. These values are exchanged via optical fibers between different supply rooms, and the considered RF signals are re-synthesized locally. These re-synthesized signals are synchronized to enable a precise phase advance control between the synchrotrons’ RF systems. The first step of the development consists in modeling the actual DDS and DSP-based LLRF environment of the SIS18 under Ptolemy-II. Measurements on real devices will be performed concurrently to the simulation. We expect to use this simulation to refine our timing expectations regarding the synchronization process and the inter-module communication protocols and design the synchronization function, which will be implemented on the hardware modules.

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WEPMA027

First Characterization of a Superconducting Undulator Mockup with the CASPER II Magnetic Measurement System

undulator, insertion, permanent-magnet, insertion-device

2815

S. Gerstl, S. Casalbuoni, N. Glamann, A.W. Grau, T. Holubek, D. Saez de Jauregui, R. Voutta
KIT, Eggenstein-Leopoldshafen, Germany
C. Boffo, T.A. Gerhard, M. Turenne, W. Walter
Babcock Noell GmbH, Wuerzburg, Germany

Superconducting insertion devices (IDs) can reach, for the same gap and period length a higher field strength compared to permanent magnet IDs. Their performance depends strongly on the magnetic field quality. While the magnetic measurements technology of permanent magnet based IDs made significant progress during the last years, for superconducting IDs similar major developments are necessary. As a part of our R&D program for superconducting insertion devices at the ANKA synchrotron light source a measurement setup for conduction cooled superconducting coils with a maximum length of 2 m was built and commissioned. In the CASPER II (Characterization Setup for Phase Error Reduction) facility the magnet coils can be trained and tested for maximum current and field quality, including the local field distribution as well as the first and second field integrals. In this paper we shortly describe the CASPER II setup and focus on the capability of this measurement device by presenting the results of a superconducting undulator mockup with a period length of 20 mm.

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WEPMN023

Vacuum System of the Storage Ring of HLS-II

vacuum, storage-ring, radiation, synchrotron-radiation

2976

Y. Wang, L. Fan, Y.Z. Hong, X.T. Pei, J. Wang, W. Wei, B. Zhang
USTC/NSRL, Hefei, Anhui, People's Republic of China

HLS storage-ring has been operated for more than twenty-five years. In 2014 we began to upgrade the machine, which is called HLS-II. The emittance is reduced to 40 nmrad, five insertion devices are added and the injection energy increases to 800MeV. Now the machine commissioning has already been completed. The typical life time is 300 mins at 300mA, 800MeV. The average pressure of static and dynamic vacuum are below 2×10^-8 Pa and 1.2×10-7 Pa respectively. The design, installation and commissioning of the vacuum system of the storage ring are detailedly stated in this paper.

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WEPMN049

Calibration of the Acceleration Voltage of Six Normal Conducting Cavities at ALBA

cavity, operation, coupling, pick-up

3036

B. Bravo, U. Iriso, J. Marcos, J.R. Ocampo, F. Pérez, A. Salom, P. Solans
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

ALBA is a 3Gev synchrotron light source located in Barcelona and operating with users since May 2012. The ALBA storage ring uses six room temperature cavities; each one fed by two 80kW IOTs amplifiers at 499.654 MHz. An accurate calibration of the RF voltage is required for the right adjustment of the beam synchronous phase. In addition, if the ring accommodates several RF cavities, these may not be optimally phased with respect to each other, complicating the calculation of the total RF voltage. In this paper, the steps to calibrate the accelerating voltage of the SR cavities will be presented and different methodologies to cross-check these calibrations.

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WEPMN062

MAX IV 3 GeV Storage Ring Magnet Block Production Series Measurement Results

dipole, storage-ring, sextupole, octupole

3069

M.A.G. Johansson, L.-J. Lindgren, M. Sjöström, P.F. Tavares
MAX-lab, Lund, Sweden

The magnet design of the MAX IV 3 GeV storage ring replaces the conventional support girder + discrete magnets scheme of previous third-generation synchrotron radiation light sources with a compact (Ø25 mm aperture) integrated design having several consecutive magnet elements precision-machined out of a common solid iron block, with mechanical tolerances of ±0.02 mm over the 2.3–3.4 m block length. The production series of 140 integrated magnet block units, which was totally outsourced to industry, was completed mid-2014, with mechanical/magnetic QA conforming to specifications. This article presents mechanical and magnetic field measurement results of the full production series.

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WEPMN066

Hall Probe Measurements of 80 Unit Cell Magnets for the MAX-IV Storage Ring

dipole, storage-ring, quadrupole, alignment

3076

A.A.F. Ahl
Scanditronix Magnet AB, Vislanda, Sweden

80 unit cell magnet segments have been manufactured by Scanditronix Magnet for the 3 GeV storage ring at MAX-IV in Lund, Sweden. All of the magnets have been approved by Max-lab after a large field measuring campaign using both a high precision hall probe bench, as well as a new rotating coil system. Each unit cell magnet consists of one dipole, two quadrupole, three sextupole and one vertical and one horizontal corrector magnets. The hall probe bench was used to measure the dipole magnet (with combined dipole and quadrupole component) as well as the quadrupole magnets. This poster will focus on the hall probe measurements performed on the dipole magnets from the perspective of a manufacturer. E.g. the repeatability of the measurements and the relation between field performance and mechanical tolerances will be analyzed.

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WEPHA012

Synchrotron Radiation Distribution and Related Outgassing and Pressure Profiles for the HL-LHC Final Focus Magnets

photon, radiation, vacuum, synchrotron-radiation

3127

R. Kersevan
CERN, Geneva, Switzerland

The HL-LHC final focus area, from D2 to the interaction point, has been modelled based on the latest vacuum chamber geometry and orbits. The synchrotron radiation (SR) fans are computed using the Monte Carlo code SYNRAD⁺, in the dipole approximation regime. The angular and energy dependence of the reflectivity of the copper surfaces is considered, as well as the surface roughness. Once the SR distributions are computed, they are converted into outstanding profiles by using data available in literature. The test-particle Monte Carlo code Molflow+ is then used and the related pressure profiles and gas density distribution are computed. This allows an optimization of the pattern of the perforations on the tungsten-shielded beam screen proposed for this area. It is shown that the resultant gas density is below the limit dictated by the ATLAS and CMS detectors.

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WEPHA028

Power Saving Status at NSSRC

controls, operation, radiation, booster

3173

J.-C. Chang, W.S. Chan, Y.C. Chang, Y.F. Chiu, Y.-C. Chung, C.W. Hsu, K.C. Kuo, Y.-C. Lin, C.Y. Liu, Z.-D. Tsai, T.-S. Ueng
NSRRC, Hsinchu, Taiwan

National Synchrotron Radiation Research Center (NSRRC), Taiwan has completed the construction of the civil and utility system engineering of the Taiwan Photon Source (TPS) in 2014. The machine is in commission currently. The power consumption is much higher than ever. Currently, the contract power capacities of the Taiwan Light Source (TLS) and the TPS with the Taiwan Power Company (TPC) are 5.5 MW and 7.5 MW, respectively. The ultimate power consumption of the TPS is estimated about 12.5 MW. To cope with increasing power requirement in the near future, we have been conducting several power saving schemes, which include adjustment of supply air temperature according to the atmosphere enthalpy, replacement of old air conditioning unit (AHU), power consumption control by the operation of chillers, power factor improvement, and reduction of power consumption during long shutdown.

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WEPHA039

Inrush Current Suppression Scheme of Hot Swap Power Modules

power-supply, controls, simulation, photon

3200

Y.T. Li, C.Y. Liu, K.-B. Liu
NSRRC, Hsinchu, Taiwan

The corrected magnet power supplies apply modular designed for Taiwan Photon Source synchrotron project (TPS). If the module is damaged in the chassis, it must to be replaced without interrupting the power. However, the modular is a shared DC bus. If there is no good design and planning, it will cause the protection circuit into action. In this article the theoretical derivation and implementation are used to prove the feasibility and necessity of the soft-start circuit. In the actual signal measurements it could be clearly seen the inrush currents is refrained and improved. Finally, the soft-start circuit is implemented applications in correction magnet power supply modular of Taiwan Photon Source synchrotron project (TPS).

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WEPHA048

Behavior of Vacuum Pressure in TPS Vacuum System

vacuum, storage-ring, booster, photon

3222

I.C. Yang, C.K. Chan, C.-C. Chang, B.Y. Chen, J.-R. Chen, C.M. Cheng, J. -Y. Chuang, G.-Y. Hsiung, C.K. Kuan, C.C. Liang, I.C. Sheng, L.H. Wu
NSRRC, Hsinchu, Taiwan

Taiwan Photon source (TPS) is in its first stage commissioning in 2014-2015. The vacuum systems of TPS were installed for commissioning since August 2014. After four months performance testing and subsystem integration, the commissioning of booster ring began on 12 December and then the first 3 GeV beam was stored on 31 December. 100mA beam current, 35Ah accumulated beam dose was archived in March 2015 before machine shut down. The average pressure in storage ring is 2.8×10^-8 Pa before commissioning, rising to 1.33×10-7 Pa with 100mA beam current. In 35Ah accumulated beam dose, the target of beam cleaning effect has reached to 8.92×10-10 Pa/mA. The vacuum performance, experience and events during commissioning will be presented in this paper.

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WEPHA049

Demagnetize Booster Chamber in TPS

booster, vacuum, dipole, operation

3225

I.C. Sheng, C.-T. Chen, C.K. Kuan, I.C. Yang
NSRRC, Hsinchu, Taiwan

Taiwan Photon Source (TPS) project starts its booster commissioning starts from August 2014. Few issues have been discovered and fixed. Since the booster aperture is relatively small and number of magnets is barely sufficient. Therefore extreme precise control of booster chamber alignment and the corresponding chamber permeability is as well important. In this paper, we present how the booster chamber is uninstalled, demagnetized and reinstalled within three weeks. This procedure is proven to result in the lowest booster chamber permeability in the world and a good high vacuum booster ring is built in 3 weeks.

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WEPTY044

Phase Transients in the Higher-Harmonic RF Systems For the ALS-U Proposal

simulation, experiment, impedance, beam-loading

3372

J.M. Byrd, S. De Santis, T.H. Luo, C. Steier
LBNL, Berkeley, California, USA

Funding: This work was supported by the Laboratory Directed Research and Development Program of Lawrence Berkeley National Laboratory under U.S. Department of Energy Contract No. DE-AC02-05CH11231.
The ALS upgrade proposal (ALS-U) requires lengthening the bunch by a factor of at least four in order to increase the beam lifetime to acceptable values. Due to the presence of gaps in the fill pattern, required by the injection/extraction kicker system, the beam-induced voltage in the passive, normal-conducting, cavities which we plan to use is not constant over the length of a bunch train. We present our result on the optimal tuning of the harmonic cavities to obtain the best lifetime increase, including the effects of strongly non-gaussian bunch shapes and wakefield distortions of the potential well.

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WEPTY065

Quadrupole Magnet for a Rapid Cycling Synchrotron

quadrupole, dipole, simulation, acceleration

3428

H. Witte, J.S. Berg
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Rapid Cycling Synchrotrons (RCS) feature interleaved warm and cold dipole magnets; the field of the warm magnets is used to modulate the average bending field depending on the particle energy. It has been shown that RCS can be an attractive option for fast acceleration of particles, for example muons which decay quickly. In previous studies it was demonstrated that in principle warm dipole magnets can be designed which can provide the required ramp rates, which are equivalent to frequencies of about 1 kHz. To reduce the losses it is beneficial to employ two separate materials for the yoke; it was also shown that by employing an optimized excitation coil geometry the eddy current losses are acceptable. In this paper we show that the same principles can be applied to quadrupole magnets targeting 30 T/m with a repetition rate of 1kHz and good field quality.

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WEPWI052

Commissioning and Early Operation Experience of the NSLS-II Storage Ring RF System

cavity, operation, storage-ring, klystron

3606

F. Gao, J. Cupolo, P. Davila, T. Dilgen, W.K. Gash, B. Holub, J.G. Kulpin, J. Papu, G. Ramirez, V. Ravindranath, B. Rose, J. Rose, R. Sikora, J. Tagger, M. Yeddulla
BNL, Upton, Long Island, New York, USA

The National Synchrotron Light Source II (NSLS-II) is a 3 GeV X-ray user facility commissioned in 2014. The storage ring RF system, essential for replenishing energy loss per turn of the electrons, consists of digital low level RF controllers, 310 kW CW klystron transmitters, CESR-B type superconducting cavities, as well as a supporting cryogenic system. Here we will report on RF commissioning and early operation experience of the system for beam current up to 200 mA.

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WEPWI055

Commissioning and Early Operation for the NSLS-II Booster RF System

booster, cavity, extraction, operation

3615

C. Marques, J. Cupolo, P. Davila, F. Gao, A. Goel, B. Holub, J.G. Kulpin, K. McDonald, J. Oliva, J. Papu, G. Ramirez, J. Rose, R. Sikora, C. Sorrentino, N.A. Towne
BNL, Upton, Long Island, New York, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-SC0012704.
The National Synchrotron Light Source II (NSLS-II) at Brookhaven National Laboratory (BNL) is a third generation 3GeV, 500mA synchrotron light source. We discuss the booster synchrotron RF system responsible for providing power to accelerate an electron beam from 200MeV to 3GeV. The RF system design and construction are complete and is currently in the operational phase of the NSLS-II project. Preliminary operational data is also discussed.

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THYC2

Recent Trends in Beam Size Measurements using the Spatial Coherence of Visible Synchrotron Radiation

optics, radiation, photon, operation

3662

T.M. Mitsuhashi
KEK, Ibaraki, Japan

The optical method of measuring the transverse beam profile and size using visible synchrotron radiation (SR) began with simple imaging systems. The resolution was limited by both the diffraction and the wavefront error making it difficult to resolve beam sizes less than 50 μm. Instead of imaging, a method for measuring the beam profile and size using the spatial coherence was introduced. The method is based on Van Cittert-Zernike’s theorem, and can resolve 4-5 μm beam sizes with an error of only 0.5 μm. In this presentation, the principle of the measurement, the SR interferometer design, and some resent measurement results are reviewed. The incoherent field depth effect for the horizontal beam size measurement is also described with some results. Design study calculations for the SR interferometer at the LHC will be presented.

Slides THYC2 [2.629 MB]

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THPF001

Tomography of Horizontal Phase Space Distribution of a Slow Extracted Proton Beam in the MedAustron High Energy Beam Transfer Line

simulation, extraction, proton, software

3673

A. Wastl
ATI, Vienna, Austria
M. Benedikt
CERN, Geneva, Switzerland
A. Garonna
EBG MedAustron, Wr. Neustadt, Austria

Funding: EBG MedAustron Marie Curie Strasse 5 A-2700 Wiener Neustadt www.medaustron.at
MedAustron is a synchrotron based hadron therapy and research center in Wiener Neustadt, Austria, which currently is under commissioning for the first patient treatment. The High Energy Beam Transfer Line (HEBT) consists of mul- tiple functional modules amongst which the phase-shifter- stepper PSS* is the most important module located where the dispersion from the synchrotron is zero and upstream of the switching magnet to the first irradiation room. The PSS is used to control the beam size for the downstream modules and for this scope rotates the beam in horizontal phase space by adjusting the phase advance. This functionality is used in this study to measure beam profiles for multiple phase space angles which act as input for a tomographic reconstruction. Simulation and measurement results are presented.
* M. Benedikt et al, A new concept for the control of a slow-extracted beam in a line with rotational optics, Nuclear Instruments and Methods in Physics Research Section A, Vol 430, Issues 2–3, 1999

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THPF134

Magnet Design and Synchrotron Damping Considerations for a 100 TeV Hadron Collider

collider, dipole, radiation, luminosity

4034

P.M. McIntyre, S. Assadi, J. Gerity, T.L. Mann, A. Sattarov
Texas A&M University, College Station, Texas, USA
D. Chavez
DCI-UG, León, Mexico
N. Pogue
PSI, Villigen, Villigen, Switzerland
M. Tomsic
Hypertech Research, Inc., Columbus, USA

A conceptual design is presented for a 100 TeV hadron collider based upon a 4.5 T NbTi cable-in-conduit dipole technology. It incorporates a side radiation channel to extract synchrotron radiation from the beam channel so that it does not produce limitations from heating on a beam liner or gas load limits on collider performance. Synchrotron damping can be used to support ‘bottom-up’ stacking to sustain maximum luminosity in the collisions.

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