PAC07 - List of Keywords (synchrotron-radiation)

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synchrotron-radiation

Paper	Title	Other Keywords	Page
MOYKI02	Commissioning of New Synchrotron Radiation Facilities	synchrotron, storage-ring, radiation, injection	17
	Z. Zhao
	Several new synchrotron radiation facilities have been commissioned over the past two years, and almost every commissioning is an impressive success with a high performance level and a swift process. In this paper, an overview of the new synchrotron radiation facilities which are coming into operation, such as Diamond, SOLEIL, Australian Synchrotron and Indus-II, is presented.
	Slides

MOOAKI02	Overall HOM Measurement at High Beam Currents in the PEP-II SLAC B-Factory	radiation, synchrotron, beam-losses, vacuum	45
	A. Novokhatski
	Funding: Work supported by US DOE contract DE-AC02-76SF00515 We describe the method to measure total HOM losses and synchrotron losses in a storage ring based on a straightforward model of beam-cavity interaction and precise knowledge of RF power distribution. This method works well at higher currents. The comparison of the measured HOM losses and estimation for cavity and resistive wall losses is given for both LER and HER rings of the PEP-II B-factory.
	Slides

MOPAN016	P3PO: An Information System for Supporting Installation Procedures at PETRA III	storage-ring, synchrotron, radiation	179
	J. Kreutzkamp L. Hagge DESY, Hamburg
	For the PETRA III project, an information system called P3PO has been developed for supporting the logistics of the installation process and for managing the technical infrastructure. P3PO provides a central information access point for the PETRA III installation status. The system registers all the components of the accelerator and provides work lists which list the tasks and their responsible groups for each component. It records the progress of work and provides support for managing the documentation. Users can access P3PO through an easy-to-use web-interface and obtain for example inventory lists, delivery status reports and task lists for groups or individuals. P3PO is based on DESYs inventory management and engineering data management systems and is in production since summer 2006. The paper describes the system capabilities and reports benefits and experience.

MOPAN027	NEG Coating of Pipes for RHIC : An Example of Industrialization Process	synchrotron, vacuum, controls, cathode	212
	A. Conte A. Bonucci, P. Manini, S. Raimondi SAES Getters S.p. A., Lainate
	Non Evaporable Getter (NEG) coated chambers have been used in various accelerators facilities and synchrotrons since some years. Initially, NEG coated chambers were mounted in small amounts in specific locations, covering a minor fraction of the accelerator surfaces exposed to vacuum. More recently, NEG coated chambers have been adopted to a larger degree in several projects, becoming an integral part of the machine design. LHC, whose commissioning is expected in 2007, will use 6 km of coated pipes, to be the largest machine ever using this technology. Other examples are the Soleil synchrotron (50% of the ring is NEG coated), ESRF (ongoing replacement of ID with NEG coated chambers) and RHIC (installation of 600 m of NEG coated pipes ongoing).Coating a large number of chambers poses challenges in term of process industrialization, product inspection and quality assurance. In the present paper we report SAES Getters' experience in the NEG coating of pipes delivered to Brookhaven National Lab for RHIC(120 steel chambers, each 5 m long). Main technological issues faced and procedures adopted to ensure product reproducibility and quality are presented and discussed.

MOPAN041	Design of a Movable Synchrotron Radiation Mask with SiC Absorber for the Photon Factory Advanced Ring (PF-AR)	synchrotron, factory, photon, klystron	248
	T. Takahashi M. Izawa, S. Sakanaka, K. Umemori KEK, Ibaraki H. Suzuki, J. Watanabe Toshiba, Yokohama
	We have six rf cavities in the Photon Factory Advanced ring (PF-AR) at KEK. Three years ago, one of them was seriously damaged by the Synchrotron Radiation (SR) from the upstream of the cavity. In order to protect the cavities from SR, we intend to install SR masks nearby the cavities. The masks have to be positioned as close as possible to the beams in order to block the SR completely during the beam storage, and as far as possible during the beam injection. Therefore SR masks should be movable. Since it is placed under strong HOM power from the cavities, careful design is necessary for power dissipation. The basic structure of the movable masks is a coaxial wave-guide with cylindrical SiC absorber whose power capability is designed to be more than 1kW. We report the design of the movable SR masks and the result of rf power test.

MOPAN095	Design of the Precise Unit for the Rotating Coil Measurement System	multipole, synchrotron, quadrupole, coupling	386
	J. C. Jan C.-H. Chang, J. W. Chen, T.-C. Fan, C.-S. Hwang, F.-Y. Lin NSRRC, Hsinchu
	A precise rotating coil measurement system (RCS) is developed to characterize the magnetic field quality of the quadrupole (QM) and sextupole (SM) magnets in the Taiwan Photon Source (TPS). A measurement bench is designed to install the magnets easily and mount the rotating coil unit with high reproducibility. The Fiberglass Reinforced Epoxy (FRP) measurement unit (F-unit) exhibits a large sag and mechanical error while it is 880mm long. Therefore, a new graphite measurement unit (G-unit) with a printed circuit coil is adopted to reduce these errors. The rotating coil design and testing using a QM are also described.

MOPAN099	Integrated Mechanism of Online Monitor and Archive System	controls, instrumentation, monitoring, synchrotron	392
	Z.-D. Tsai J.-C. Chang, T.-S. Ueng NSRRC, Hsinchu
	In the accelerator field, the instrumentation monitor system provides the machine online status to view, control and alert. A novel shared data engine developed by Labview provides the distributed PCs, PDAs, embedded devices, and local controllers to exchange data mutually via Ethernet or wireless Ethernet. The mechanism guarantees delivery with an additional function layer of the raw UDP protocol and usees less network bandwidth than TCP/IP. The system's main function is to introduce a platform with reliable online information about the status of the instrumentation. The users can access data with graphic view and trend view by some complementary software. Also, the users can easily take the online data via binding monitor tags without programming. The mechanism benefits all system maintenance, operation, management and analysis.

MOPAN101	Failure Analysis for Cryogenic System Operation at NSRRC	cryogenics, superconducting-magnet, controls, synchrotron	398
	H. H. Tsai S.-H. Chang, W.-S. Chiou, F. Z. Hsiao, H. C. Li NSRRC, Hsinchu
	Two 450W cryogenic systems were installed on the year 2002 and 2006, respectively at NSRRC. So far, one 450W cryogenic system is cooling two superconducting magnets and one superconducting cavity. The new system will serve for five superconducting magnets on the year 2007. This paper presents the abnormal operation for the system, which induces the fluctuations for pressure, temperature, and flow rate, respectively. Solutions for these failures are shown and discussed.

TUOBAB02	Experimental Characterization of the Transverse Phase Space of a 60-MeV Electron Beam through a Compressor Chicane	electron, linac, synchrotron, simulation	788
	F. Zhou R. B. Agustsson, G. Andonian, D. B. Cline, A. Y. Murokh, J. B. Rosenzweig UCLA, Los Angeles, California A. C. Kabel SLAC, Menlo Park, California V. Yakimenko BNL, Upton, Long Island, New York
	Funding: U. S. DOE of Sciences Space charge and coherent synchrotron radiation may deteriorate electron beam quality when the beam passes through a magnetic bunch compressor. This paper presents the transverse phase-space tomographic measurements for a compressed beam at 60 MeV, around which energy the first stage of magnetic bunch compression takes place in most advanced linacs. Transverse phase-space bifurcation of a compressed beam is observed at that energy, but the degree of the space charge-induced bifurcation is appreciably lower than the one observed at 12 MeV. The Trafic4 simulation confirms the observation. The paper was published at PRST-AB, November 2006
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TUPMN058	The Operation Status of HLS (Hefei Light Source)	radiation, synchrotron, damping, feedback	1058
	W. Li G. Feng, L. Liu, B. Sun, J. H. Wang, L. Wang, H. Xu, K. Xuan USTC/NSRL, Hefei, Anhui S. C. Zhang USTC, Hefei, Anhui
	National Synchrotron Radiation Lab, University of Science and Technology of China, P. R.China HLS(Hefei Light Source) is a dedicated synchrotron radiation research facility, spectrally strongest in Vacuum Ultra Violet and Soft X-ray. Designed and constructed in 1980's, accepted to regular service in 1991. From 1999 to 2004, the National Synchrotron Radiation Lab carried out its Phase II Project, in which quite a few sub-systems of HLS storage ring were upgraded and 8 new beamline were constructed. After the project, the performance of HLS is improved considerably. In this paper, the operation status and performance of storage ring in recent years were presented. With some measures, the operation beam intensity is about 300mA, beam lifetime is higher than before, orbit stability is met requirement of users, and the capability to provide synchrotron radiation exceeds the design value.

TUPMS026	Design of Control Instrumentation of two In-Vacuum Undulators IVU25s	controls, vacuum, synchrotron, undulator	1236
	J. Kulesza N. Chen SSRF, Shanghai A. Deyhim Advanced Design Consulting, Inc, Lansing, New York
	Funding: Shanghai Institute of Applied Physics This paper summarizes the primary controller that is based on Schneider Premium PLC for two in-vacuum undulators to be installed at SSRF. The PLC controls a single gap stepper motor and driver, both made by Parker-Hannifin. Position feedback is derived from a TR Electronics linear absolute LTS-240 encoder mounted across the gap. The encoder resolution is programmable down to .1 um per count. Since the encoder is absolute there will be no need to home the gap axis. The advantage of linear encoders is the measurement is more direct and is not subject to wind-up and deflection that a rotary encoder would see on the end of a ball screw. Two encoders are planned, one on each end of the magnet array. One encoder will be the primary feedback for the axis and the other will detect deflection errors and girder taper. Four limits are provided as well as 4 kill switches. The 4 switches (2 limits and 2 kills) at min gap are optical and the 4 outer switches (2 limits and 2 kills) are mechanical. The limits prevent further motion in the direction they protect but allow the axis to be driven in the other direction (off the switch).

TUPMS044	Design of a 980 MeV Energy Recovery Linac	linac, recirculation, quadrupole, synchrotron	1287
	R. A. Bosch J. Bisognano, M. D. Medley UW-Madison/SRC, Madison, Wisconsin
	Funding: This research was supported by National Science Foundation grant no. DMR-0537588. A 980-MeV energy recovery linac with radiofrequency (rf) of 1.5 GHz is designed. Electrons are accelerated by two passages through a 480-MeV superconducting linac, and decelerated by two subsequent passages. Recirculation is accomplished with six 60-degree bending magnets. The threshold current for beam breakup instability exceeds 100 mA. Gaussian bunches with normalized transverse emittances of 0.1 mm-mrad and rms length of 1.85 ps may be compressed by a factor of 180 (to a bunch length of 10 fs) with only a slight increase in transverse normalized emittance. Bunch charges up to 8 pC may be compressed at 980 MeV without excessive degradation from coherent synchrotron radiation, allowing operation with beam currents up to 12 mA.

TUPAS032	Prospects of Diagnostics with Optical Diffraction Radiation in Hadron Colliders	radiation, target, collider, synchrotron	1721
	T. Sen V. E. Scarpine, R. Thurman-Keup Fermilab, Batavia, Illinois
	Optical diffraction radiation has been observed and recently used to measure the beam size of electrons at KEK. This non-invasive technique also holds promise for imaging beams close to the interaction point in hadron colliders. In this paper we consider the feasibility of this technique for the Tevatron and the LHC.

WEOAC01	Secondary Electron Yield and Rectangular Groove Chamber Tests in PEP-II	electron, radiation, synchrotron, vacuum	1997
	M. T.F. Pivi R. E. Kirby, T. W. Markiewicz, T. O. Raubenheimer, J. Seeman, L. Wang SLAC, Menlo Park, California F. Le Pimpec PSI, Villigen
	Funding: Work supported by the Director, Office of Science, High Energy Physics, U. S. DOE under Contract No. DE-AC02-76SF00515. Possible remedies for the electron cloud in the Damping Ring of the International Linear collider includes conditioning of the surface and chamber with grooves. We installed chambers in PEP-II to test the secondary electron yield (SEY) of coated TiN and TiZrV NEG samples and study the effect of electron and photon conditioning in situ. We have also installed vacuum chambers with rectangular groove profile in straight sections to test this possible mitigation technique. In this paper, we will describe the PEP-II test layout, results and impact on impedance.

WEPMN007	Introducing a Homepage for Information Retrieval and Backup of the Ground Vibration Measurements and Mechanical Vibrations of the Superconducting Modules at DESY	site, ground-motion, background, synchrotron	2059
	R. Amirikas M. Kubczigk DESY, Hamburg
	Funding: Work supported by the Commission of the European Communities under the 6th Framework Program Structuring the European Research Area, contract number RIDS-011899. In this paper, we will introduce our homepage (http://vibration.desy.de) which is used for the storage and dissemination of our ground motion measurement data of 20 sites around the world and the XFEL/ILC superconducting module data. This homepage is open to the scientific community and the data can be utilized for planning of future accelerator facilities and design of future prototypes of module vessels containing cold mass.

WEPMS011	Comparative Surface Studies on Fine-grain and Single Crystal Niobium Using XPS, AES, EBSD and Profilometry	superconductivity, electron, survey	2349
	A. Romanenko G. V. Eremeev CLASSE, Ithaca H. Padamsee, J. B. Shu Cornell University, Ithaca, New York
	Funding: Supported by NSF As the surface magnetic field in niobium cavities approaches the theoretical critical field, rf losses begin to grow sensitive to increasingly subtle features of the material and the surface. A striking example is the familiar occurrence of the high-field Q-slope, where rf losses increase exponentially with field above an onset field. A surprising feature of the high-field Q slope is its positive response to mild baking at 120 C. But the Q-slope returns after the first 20 nm of the niobium metal surface is converted to loss-less pentoxide via anodization, a key feature. The latter result suggests that the cause of the fast growing losses resides in the first 20 nm of the rf surface. Although there are several propositions, the exact mechanism for the high-field Q-slope is not yet fully understood and demands further research. We are conducting surface analytic studies with XPS, SIMS, and Auger to shed light on the mechanism of the high-field Q-slope. We are comparing the behavior of fine-grain samples with single crystal samples, BCP treatments with EP treatments and properties before and after 120 C bake. We also study the effect of baking at temperatures up to 400 C.

THYC02	Coherent Radiation Diagnostics for Short Bunches	radiation, diagnostics, synchrotron, electron	2653
	O. Grimm
	Electron bunches less than a few picoseconds emit lots of coherent radiation (CSR, CTR, CDR, etc.) most of which is at terahertz frequencies. This is becoming the diagnostic of choice for bunch compressors in linacs (chicanes). However, at these frequencies the transmission of the radiation can be very challenging. Signifiicant advances, with examples of real measurements at TTF2, will be described.
	Slides

THOBC02	Absolute Bunch Length Measurements at the ALS by Incoherent Synchrotron Radiation Fluctuation Analysis	radiation, photon, synchrotron, electron	2661
	F. Sannibale D. Filippetto INFN/LNF, Frascati (Roma) G. V. Stupakov SLAC, Menlo Park, California M. S. Zolotorev LBNL, Berkeley, California
	Funding: This work is supported by the Director, Office of Science, High Energy Physics, U. S. Dept. of Energy under Contract no. DE-AC02-05CH1121 By analysing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and tested a simple scheme based on this principle that allows for the absolute measurement of the bunch length. A description of the method and the experimental results are presented.
	Slides

THPMN109	Status of the ILC Main Linac Lattice Design	linac, lattice, synchrotron, quadrupole	2966
	A. Valishev N. Solyak Fermilab, Batavia, Illinois M. Woodley SLAC, Menlo Park, California
	The report describes the present design of the ILC Main Linac lattice. The topics covered include basic element layout, optical functions, and issues centered around the linac following of the Earth's curvature. Also discussed are beam parameter measurements and instrumentation requirements.

THPAN034	New Simulation Code for Synchrotron Radiation Based on a Real Beam Orbit	simulation, monitoring, synchrotron, alignment	3304
	T. Abe
	A computer code to simulate synchrotron-radiation power and spatial distributions has been developed based on the method by T. Abe and H. Yamamoto, where a real beam orbit is obtained by fitting measurements of beam-position monitors (BPMs) with some offset corrections for BPMs and magnet alignments. In this paper, the basic performance and application are presented. This code has been rewritten in Fortran95 so as to obtain expectable maximal speed-up by parallel computing, aiming at online alarm systems to take precautions against synchrotron-radiation damage, toward higher beam current accelerators. T. Abe and H. Yamamoto, Phys. Rev. ST Accel. Beams 7, 072802 (2004)

THPAN055	Theoretical Study of Medium Emittance Lattice at HLS	lattice, emittance, synchrotron, dynamic-aperture	3351
	H. Hao G. Feng, W. Li, L. Wang, X. Wang, H. Xu USTC/NSRL, Hefei, Anhui S. C. Zhang USTC, Hefei, Anhui
	Funding: Supported by National Natural Science Foundation of China, No. 10175062 & No.17175100 A method of injection analysis of small electron storage ring is introduced, and several medium emittance lattices are proposed. By analyzing the injection, working point of the lattice is selected at the vicinity of half integer resonance lines, and emittance is around 60nmrad, the linear and nonlinear properties can be satisfied for injection and store. LIU Zu-Ping, Li Wei-Min. Progress of the NSRL Phase Two Project. In proceedings of the Second Asia Particle Accelerator Conference, Beijing, China, 2001, 235-238

THPAN087	Study of Turn-by-Turn Vertical Beam Dynamics at Low and High Energy CESR Operation	electron, positron, synchrotron, radiation	3423
	R. Holtzapple G. W. Codner, M. A. Palmer, E. Tanke CESR-LEPP, Ithaca, New York J. S. Kern Alfred University, Alfred, New York
	Funding: This work was supported by the National Science Foundation. Presently, CESR is operated at two different beam energies, low energy (E=2GeV) for high energy physics (CESR-c), and high energy (E=5.3GeV) for synchrotron radiation production (CHESS). The electron and positron bunches vertical dynamics at these two energies are vastly different, in part due to the change in the pretzel orbit, the presence of wiggler magnets at low energy, and synchrotron radiation power at two vastly different energies. Using the 32 channel photomultiplier array, we measured the vertical beam dynamics on a turn-by-turn basis during CHESS and CESR-c operation as well as dedicated machine studies time. For these studies we quantify the electron cloud effects such as vertical tune shift and vertical beam size blow-up along the electron and positron trains at these two vastly different beam energies. In addition, the turn-by-turn capability of the PMT array allows us to study the vertical bunch dynamics over 10k turns. Design and Implementation of an Electron and Positron Multibunch Turn-by-Turn Vertical Beam Profile Monitor in CESR-PAC2007 proceedings

THPAS045	Method of Perturbative-PIC Simulation for Interactions between a Bunch and Its Synchrotron Radiation	radiation, simulation, synchrotron, lattice	3594
	J. Shi G. Hoffstaetter CLASSE, Ithaca
	Funding: This work is supported by the US Department of Energy under Grant No. DE-FG02-04ER41288. A self-consistant simulation method is developed for the study of coherent synchrotron radiation effects by using a perturbation expansion of retarded radiation field and the particle-in-cell method. The perturbation expansion of the radiation field is based on the fact that the time dependance of a bunch particle distribution has typically two significantly different time scales, a fast time scale related to the linear dynamics and a slow time scale of the beam-size growth due to nonlinear perturbations. Since the scale of the retardation of the radiation field is usually much shorter than the slow time scale of the particle distribution, the retardation on the slow time scale of the particle distribution is treated perturbatively while the retardation on the fast time scale is removed by transformations associated the linear lattice. With this method, the particle-radiation interaction can be calculated in configuration space without memorizing the history of the particle distribution.

FRPMN015	Simulation of Synchrotron Radiation at the First Bunch Compressor of FLASH	simulation, radiation, synchrotron, vacuum	3925
	A. Paech W. Ackermann, T. Weiland TEMF, Darmstadt O. Grimm DESY, Hamburg
	Funding: This project is supported by the Helmholtz Association under contract HGF-VH-FZ-006 One method to measure the bunch shape at the FLASH facility at DESY, Hamburg is based on the observation of synchrotron radiation generated at the first bunch compressor. For the correct interpretation of the results it is mandatory to know how various parameters of the real setup, in contrast to theoretical assumptions, influence the observed spectrum. The aim of this work therefore is to calculate the generation of synchrotron radiation of a moving point charge inside the bunch compressor with the emphasis of including the effects of the vertical and horizontal vacuum chamber walls in the vicinity of the last dipole magnet. Because of the small wavelength in comparison with the chamber geometries this is a demanding task. One idea to cope with the difficulties is to use optical methods such as the uniform theory of diffraction (UTD). In this paper the applicability and limitations of the proposed method are discussed. Furthermore a comparison of simulated and new measured fields is shown.

FRPMN035	Crabbing Angle Measurement by Streak Camera at KEKB	luminosity, optics, synchrotron, betatron	4018
	H. Ikeda J. W. Flanagan, H. Fukuma, S. Hiramatsu, T. Mitsuhashi KEK, Ibaraki
	Crab cavities will be installed in the KEKB rings in order to increase luminosity. We measure the crabbing angle using a streak camera and show the results in this paper.

FRPMS071	Relative Bunch Length Monitor for the Linac Coherent Light Source (LCLS) using Coherent Edge Radiation	radiation, electron, dipole, synchrotron	4189
	H. Loos T. Borden, P. Emma, J. C. Frisch, J. Wu SLAC, Menlo Park, California
	Funding: This work was supported by U. S. Department of Energy, Office of Basic Energy Sciences, under Contract DE-AC03-76SF00515 The ultra-short bunches of the electron beam for LCLS are generated in two 4-dipole bunch compressors located at energies of 250 MeV and 4.3 GeV. Although an absolute measurement of the bunch length can be done by using a transverse deflecting cavity in an interceptive mode, a non-interceptive single shot method is needed as a relative measurement of the bunch length used in the continuous feedback for beam energy and peak current. We report on the design and implementation of two monitors measuring the integrated power of coherent edge radiation from the last dipole in each chicane. The first monitor is installed in early 2007 and we compare its performance with the transverse cavity measurement and other techniques.

FRPMS083	Coherent Synchrotron Radiation and Space Charge for a 1-D Bunch on an Arbitrary Planar Orbit	space-charge, radiation, synchrotron, vacuum	4255
	R. L. Warnock
	Funding: Supported in part by Department of Energy contract DE-AC02-76SF00515. Realistic modeling of coherent synchrotron radiation (CSR) and the space charge force in single-pass systems and rings usually requires at least a two-dimensional (2-D) description of the charge/current density of the bunch. Since that leads to costly computations, one often resorts to a 1-D model of the bunch for first explorations. This paper provides several improvements to previous 1-D theories, eliminating unnecessary approximations and physical restrictions.