IBIC2013 - List of Keywords (vacuum)

Paper	Title	Other Keywords	Page
MOPC02	Status of Beam Diagnostics for NSLS-II Booster	booster, controls, BPM, diagnostics	41
	V.V. Smaluk, E.A. Bekhtenev, S.E. Karnaev, G.V. Karpov, O.I. Meshkov BINP SB RAS, Novosibirsk, Russia D. Padrazo, O. Singh, V.V. Smaluk, K. Vetter, G.M. Wang BNL, Upton, Long Island, New York, USA
	For the NSLS II third generation light source, a full-energy Booster ring has been designed and produced by Budker Institute of Nuclear Physics. For the Booster commissioning and operation, following beam diagnostic instruments have been designed and manufactured: 6 beam flags, 36 electrostatic pickups with BPM receivers, 2 synchrotron light monitors (SLMs), 1 DC current transformer, 1 fast current transformer, Tune Measurement System (TMS) including 2 strip-line assemblies. All the equipment has been installed in the Booster ring and Injector Service Area. Control software of the beam diagnostic devices has been developed and incorporated into the NSLS-II control system using the EPICS environment. A number of high-level applications has been developed using Control System Studio and Python. The Integrated Testing and the System Level Testing have been performed. Current status of the Booster beam diagnostic instrumentation is reviewed.

MOPF01	Transverse Beam Size Measurements Using Interferometry at ALBA	transverse, synchrotron, dipole, radiation	193
	U. Iriso, L. Torino CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain T.M. Mitsuhashi KEK, Ibaraki, Japan
	Double-slit interferometry using visible light has been used for measuring the transverse beam size in different accelerators. The beam size is inferred from the analysis of the spatial coherence of the synchrotron light produced by a bending magnet. At ALBA, this technique has been implemented with moderate success, mainly limited by the present imperfections in the in-vacuum mirror that is used to extract the light out of the vacuum chamber. In this paper, we report the results obtained with the current set-up, and discuss possible improvements.

MOPF05	Operating Semiconductor Timepix Detector with Optical Readout in an Extremely Hostile Environment of Laser Plasma Acceleration Experiment	laser, target, shielding, optics	208
	L. Pribyl Czech Republic Academy of Sciences, Institute of Physics, Prague, Czech Republic
	The laser plasma acceleration (LPA) experiments produce very intensive electromagnetic pulses (EMP) complicating operation of sensitive electronic detectors. We present our experience with new optical readout and EMP shielding for hybrid silicon pixel detector Timepix, which enabled its operation in an extremely hostile electromagnetic LPA environment. The Timepix detector provides a matrix of 256x256 spectroscopic channels with 55 μm pitch. An optical readout, battery powering and shielding against electromagnetic pulses (EMP) have been developed as part of the ELI Beamlines/IEAP project for the detector Timepix and it significantly improved its resistance to EMP with respect to previous setup using metallic cables for both data acquisition and powering. The new optical setup was successfully tested under vacuum at Prague Asterix Laser System (PALS) during experiments with laser pulses of energies up to 700 J and duration of 350 ps bombarding thin foil solid target. Electromagnetic field was measured both outside the vacuum chamber and inside. The recorded spectrometric data were analyzed and interpreted in a context of an independent experimental campaign run in parallel. X. Llopart et al.: Timepix, a 65k Programmable Pixel Readout Chip for Arrival Time, Energy and/or Photon Counting Measurements, Nucl. Instr. and Meth. in Phys. Res. A. Vol. 581 (2007), p485

MOPF24	Magnetic Materials for Current Transformers	CERN, impedance, damping, GSI	263
	S. Aguilera, P. Odier, R. Ruffieux CERN, Geneva, Switzerland
	At CERN, the circulating beam current measurement is provided by two types of transformers, the Direct Current Current Transformers (DCCT) and the Fast Beam Current Transformers (FBCT). Each type of transformer requires different magnetic characteristics regarding parameters such as permeability, coercivity and shape of the magnetization curve. Each transformer is built based on toroidal cores of a magnetic material which gives these characteristics. For example, DCCTs consist of three cores, two for the measurement of the DC component and one for the AC component. In order to study the effect of changes in these parameters on the current transformers, several interesting raw materials based on their as-cast properties were selected with the annealing process used to tune their properties for the individual needs of each transformer. First annealing tests show that the magnetization curve, and therefore the permeability, of the material can be modified, opening the possibility for building and studying a variety of transformer cores.
	Poster MOPF24 [1.185 MB]

MOPF27	A Beam Current Monitor for the VECC Accelerator	linac, gun, diagnostics, radiation	275
	W.R. Rawnsley, R.E. Laxdal TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	TRIUMF is building VECC, the first stage of a 50 MeV electron linac. Beam diagnostic devices will be inserted radially into 8-port vacuum boxes. RF shields, 6.3 cm dia. tubes perforated by pump out slots, can be inserted to reduce wakefields. They will also serve as capacitive probes picking up harmonics of the 650 MHz bunch rate. 100 mV P/P was measured for 3 mA at 100 kV. A SC cavity will accelerate the beam to 10 MeV. The dump current is limited by the shielding to 300 W. We will use a 3 mA beam at 1% duty cycle. Two RF shields will monitor the current. A newly developed circuit will give dc outputs proportional to the peak and average current. It uses a log detector with range of 70 dB for 1 dB of error and a rise and fall time of ~20 ns. Terasic development boards process the log signal. It is digitized by a 14-bit ADC at a 50 MHz rate and passed to a FPGA programmed in Verilog. Altera Megafunctions offset, scale, convert to floating point, antilog and filter the signal in a pipeline architecture. Two 14-bit DACs provide the outputs. Digital processing maintains the wide dynamic range. Beam pulses can be <250 ns and the sample rate insures accuracy at low duty cycle.
	Poster MOPF27 [1.314 MB]

MOPF29	A Non-Invasive Beam Monitor for Hadron Therapy Beams	proton, CERN, target, LHC	283
	T. Cybulski, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom T. Cybulski, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom A. Kacperek, B. Marsland, I. Taylor, A. Wray The Douglas Cyclotron, The Clatterbridge Cancer Centre NHS Foundation Trust, Wirral, United Kingdom
	Funding: Work supported by the EU under contract PITN-GA-2008-215080 and the STFC Cockcroft Institute Core Grant No. ST/G008248/1 Hadron therapy allows for precise dose delivery to the tumour volume only and hence decreases the dose delivered to the nearby organs and healthy tissue. Ideally, the beam would be monitored whilst being delivered to the patient. A novel, real–time and non-interceptive beam monitor for hadron therapy beams has been developed in the QUASAR Group. It is based on the LHCb VErtex LOcator (VELO) detector and couples to the treatment beam’s transverse halo to determine the intensity, position and ultimately the dose of the treatment beam. This contribution presents the design of a stand-alone version of the VELO detector which was developed for the Clatterbridge Cancer Centre (CCC) treatment line. The mechanical and electronic design of the monitor and its data acquisition system are shown, with a focus on the detector positioning and cooling system. Monte Carlo simulations into expected signal distributions are compared against first measurements with the 60 MeV proton beam at CCC.

MOPF31	Design and Performance of the Biased Drift Tube System in the BNL Electron Lens	RHIC, electron, beam-losses, ion	291
	T.A. Miller, W. Fischer, D.M. Gassner, X. Gu, A.I. Pikin, S. Polizzo, P. Thieberger BNL, Upton, Long Island, New York, USA J. Barth Barth Electronics, Boulder City, USA
	Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy. The installation of the Electron Lenses in RHIC will be completed this year. Its design includes a series of drift tubes through which the electron beam copropagates, with the RHIC proton beams. These drift tubes are used to create an electric field gradient to sweep out ions that become trapped within the central magnetic field where the electron beam interacts with the proton beams. These isolated drift tubes are biased by high voltage power supplies. Without a path for the proton beam image currents, high voltages will develop on the drift tubes that can be detrimental to the electron beam and increase the RHIC machine impedance. This paper presents the design of the drift tubes, axial electric field gradient, and the custom high voltage RF bias tees that were designed to provide separate paths for the high frequency image currents and the DC high voltage bias over the same cables. The design and simulation of the bias tee is discussed, as well as RF signals from the proton beam current imaged on the drift tubes, as measured through the bias tees during the commissioning of the blue RHIC beam electron lens this past spring.
	Poster MOPF31 [31.237 MB]

MOPF34	Nuclotron Deuterons Beam Parameters Measurements Using SSNTD	target, dipole, quadrupole, synchrotron	299
	K.V. Husak, V.V. Bukhal The Joint Institute of Power and Nuclear Reserach - "SOSNY" NASB, Minsk, Belarus M. Artiushenko, V.V. Sotnikov, V.A. Voronko NSC/KIPT, Kharkov, Ukraine A.A. Patapenka, A.A. Safronava, I.V. Zhuk JIPNR-Sosny NASB, Minsk, Belarus
	ADS are considered as prospective nuclear installations for energy production and nuclear waste transmutation or recycling. The international project “Energy and Transmutation Radioactive Wastes” running in the Laboratory of High Energy Physics at JINR (Dubna, Russia) at the accelerator complex “Nuclotron” is aimed at a feasibility study of using a deeply subcritical natural or depleted uranium or thorium active core with very hard neutron spectrum inside for effective burning of the core material together with spent nuclear fuel. For any ADS experiment a necessary and a key element is beam diagnostics. In this paper a technique for precise measurement of deuteron beam parameters using SSNTD, developed within the bounds of “E&T RAW” project, is presented. The deuteron beam parameters, specifically beam shape, size and position on a target, are obtained from track density distribution on the irradiated track detectors. The presented technique has a resolution of 1 mm. The experimental results of beam parameter measurements for deuterons with energies of 2, 4 and 8 GeV at the irradiation of the uranium subcritical assembly “QUINTA”, obtained with the SSNTD technique, are presented.
	Poster MOPF34 [0.826 MB]

TUPC07	Design and Impedance Optimization of the SIRIUS BPM Button	BPM, impedance, storage-ring, longitudinal	365
	H.O.C. Duarte, S.R. Marques, L. Sanfelici LNLS, Campinas, Brazil
	Design of several BPM Buttons is presented with detail impedance, heat transfer and mechanical analysis. Special attention is given to the application of ceramics as materials with low relative permittivity inside of the BPM Button and to the geometric shape of the BPM Button. The heat dissipation is evaluated based on the loss factor calculated for a 2.65mm bunch length. The narrow-band impedance is discussed and its dependence on applied ceramic materials is compared.
	Poster TUPC07 [1.715 MB]

TUPC11	Beam-Based Measurement of ID Taper Impedance at Diamond	impedance, transverse, simulation, BPM	380
	V.V. Smaluk, R. Bartolini, R.T. Fielder, G. Rehm Diamond, Oxfordshire, United Kingdom
	New insertion devices (IDs) are being designed now for a Diamond upgrade. One of the important topics of the design is the coupling impedance of the ID vacuum chamber movable tapers. To get a complete and reliable information of the impedance, analytical estimations, numerical simulation and beam-based measurement have been performed. The impedance of an existing ID taper geometrically similar to the new one has been measured using the orbit bump method. It turns out that in spite of the small magnitude (a few um) of orbit distortion to be observed in this case, the BPM resolution is sufficient for this measurement. The measurement results in comparison with simulation data are discussed in this paper.

TUPC37	Presentation of the Smith-Purcell Experiment at SOLEIL	radiation, SOLEIL, linac, longitudinal	460
	N. Delerue, J. Barros, S. Jenzer, M. Vieille Grosjean LAL, Orsay, France L. Cassinari, M. Labat SOLEIL, Gif-sur-Yvette, France G. Doucas, I.V. Konoplev, A. Reichold JAI, Oxford, United Kingdom A. Faus-Golfe, N. Fuster Martinez, J. Resta-López IFIC, Valencia, Spain
	Funding: Work supported by seed funding from Université Paris-Sud, program 'Attractivité' and by the French ANR under contract ANR-12-JS05-0003-01. The potential of Coherent Smith-Purcell radiation as a longitudinal bunch profile monitor has already been demonstrated and has recently been extended to the sub-picosecond range. As a critical step toward the construction of a single shot bunch profile monitor using Coherent Smith-Purcell radiation it is important to measure very accurately the distribution of such radiation. Optimum background suppression techniques need to be found and relatively cheap detectors suitable for the far infra-red need to be qualified. To perform these tasks a test stand has been installed at the end of the linac of the synchrotron SOLEIL. This test stand and the first results from its commissioning will be presented here.

TUPF25	Beam Current Measurement System in CSNS LINAC	linac, beam-transport, SNR, instrumentation	565
	P. Li, F. Li, M. Meng, T.G. Xu IHEP, Beijing, People's Republic of China
	The China Spallation Neutron Source is being constructed at Dongguan, Guangdogn province. Before RCS Ring there are three beam transport sections in CSNS LINAC : LEBT, MEBT, LRBT, where various beam measurement monitors will be installed. Beam Current Transformers (BCTs) have been designed to measure beam macro-pulse current that will operate between 5mA to 80mA . The BCTs have the same inductance but different size in these three sections. Besides, beam parameters should be monitored also between the DTL four parts. There is no BCT but a FCT would be installed after DTL1 due to space limit. So this FCT is planned to measure the macro-pulse current, and we have to proceed the acquired data to show the original macro-pulse waveform due to the FCT’s low inductance.
	Poster TUPF25 [0.736 MB]

TUPF36	Analysis of Modulation Signals Generated in the TE Wave Detection Method For Electron Cloud Measurements	electron, resonance, BPM, pick-up	605
	S. De Santis LBNL, Berkeley, California, USA J.P. Sikora Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: Work supported by the U.S. Department of Energy and by the US National Science Foundation under Contracts No. DE-AC02-05CH11231, DE-FC02-08ER41538, DE-SC0006505, PHY-0734867, PHY-1002467. The evaluation of the electron cloud density in storage rings by measuring its effects on the transmission of electromagnetic signals across portions of the beampipe is a widely used technique and the most suited for measurements over extended regions. Recent results show that in a majority of cases the RF signal transmission takes place by coupling to standing waves excited in the vacuum chamber. In such a case the effect of a varying cloud density is a simultaneous amplitude, phase and frequency modulation of a fixed frequency drive signal. The characteristics of the modulation depend not only on the cloud density values and spatial distribution, but also on its temporal evolution and on the damping time of the standing waves. In this paper we evaluate the relationship between measured modulation sidebands amplitude and the electron cloud density when cloud and electromagnetic resonance rise and fall times are of the same order of magnitude, as it is the case in the accelerators where we have conducted our experiments.

WEAL2	Extremely Low Emittance Beam Size Diagnostics with Sub-Micrometer Resolution Using Optical Transition Radiation	OTR, laser, electron, transverse	615
	K.O. Kruchinin, S.T. Boogert, P. Karataev, L.J. Nevay Royal Holloway, University of London, Surrey, United Kingdom A.S. Aryshev, M.V. Shevelev, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan B. Bolzon The University of Liverpool, Liverpool, United Kingdom B. Bolzon, T. Lefèvre, S. Mazzoni CERN, Geneva, Switzerland
	Transverse electron beam diagnostics is crucial for stable and reliable operation of the future electron-positron linear colliders such as CLIC or Higgs Factory. The-state-of-the-art in transverse beam diagnostics is based on the laser-wire technology. However, it requires a high power laser significantly increases the cost of the laser-wire system. Therefore, a simpler and relatively inexpensive method is required. A beam profile monitor based on Optical Transition Radiation (OTR) is very promising. The resolution of conventional OTR monitor is defined by a root-mean-square of the so-called Point Spread Function (PSF). In optical wavelength range the resolution is diffraction limited down to a few micrometers. However, in * we demonstrated that the OTR PSF has a structure which visibility can be used to monitor vertical beam size with sub-micrometer resolution. In this report we shall represent the recent experimental results of a micron-scale beam size measurement. We shall describe the entire method including calibration procedure, new analysis, and calculation of uncertainties. We shall discuss the hardware status and future plans. * P. Karataev et al., Physical Review Letters 107, 174801 (2011).
	Slides WEAL2 [5.120 MB]

WECL2	Radiation Damages and Characterization in the SOLEIL Storage Ring	radiation, quadrupole, dipole, SOLEIL	644
	N. Hubert, P. Brunelle, N. Béchu, L. Cassinari, C. Herbeaux, S. Hustache, J.-F. Lamarre, P. Lebasque, F. Marteau, A. Nadji, L.S. Nadolski SOLEIL, Gif-sur-Yvette, France
	After six years of operation, equipment located close to some vacuum chambers of the SOLEIL storage ring show unexpected damages due to radiation. It has been pointed out that, inside the so called “quadrupole” vacuum chambers, fluorescence X-rays are emitted by the materials that intercept upstream dipole synchrotron radiation. The energy of the emitted X-ray is too high to be significantly attenuated by the aluminum of which the vacuum chamber is made. Diagnostics and means used to characterize this radiation are presented, and measurements are compared to calculations.
	Slides WECL2 [2.336 MB]

WEPC03	Brookhaven 200 MeV Linear Accelerator Beam Instrumentation Upgrade	linac, instrumentation, diagnostics, radiation	656
	O. Gould, B. Briscoe, D.M. Gassner, V. LoDestro, R.J. Michnoff, J. Morris, D. Raparia, K. Sanders, W. Shaffer, C. Theisen, M. Wilinski BNL, Upton, Long Island, New York, USA D. Persaud City College of The City University of New York, New York, USA
	The Brookhaven National Laboratory 200 MeV H⁻ LINAC beam instrumentation equipment has been in operation for four decades with various changes implemented over this period. There is a need to upgrade the entire beam instrumentation system of the LINAC to improve the diagnostics of the beam from the Low Energy Beam Transport Line through the LINAC and into the LINAC Booster Transfer Line and BLIP line. Profile Monitors, Current Monitors, Beam Position Monitors, Loss Radiation Monitors, and Emittance Measurement devices are to be designed and implemented over the next three years. This upgrade will improve the operation reliability, beam quality and beam losses. Additional improvements will be obtained by designing the beam instrumentation system to integrate with other proposed diagnostics and malfunction detection and display upgrades in the LINAC Control Room to improve the overall performance of the LINAC.
	Poster WEPC03 [18.356 MB]

WEPC09	Performance of NSLS2 Button BPM	BPM, simulation, storage-ring, booster	678
	W.X. Cheng, B. Bacha, B.N. Kosciuk, S. Krinsky, O. Singh BNL, Upton, Long Island, New York, USA
	Several types of button BPMs are used in NSLS2 complex. Coaxial vacuum feedthroughs are used to couple the beam induced signal out. The feedthroughs are designed to match the external transmission line and electronics with characteristic impedance of 50 Ohm. Performances of these BPM feedthroughs are presented in this paper.

WEPC26	Pickup Electrode Electrodynamics Investigation	pick-up, LEFT, transverse, impedance	742
	A. Kalinin STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Waves induced in a pickup by beam were investigated on a large scale model, using 10ps step in coaxial line as beam, and a differentiating capacitive probe. The probe signal was observed at 20GHz oscilloscope. In each of the front and rear transverse gaps between pickup electrode and wall (button pickup), a shorter-than-gap bunch excites a ‘plain-wave’ packet which length is of the order of gap length over c. Two packets are spaced by electrode length over c. The packets propagate along the electrode to a coaxial connector. At this low impedance common point each of the packets partially reflects back and partially passes into the opposite gap. The voltage appearing on the impedance excites two TEM-wave packets: one propagates backwards, another one propagates forward through connector. The connector output is sum of two such packets spaced the same as two incident packets. The packets propagating backwards reflect from the electrode open end, come back to the summing point and generate output in similar way. The same processes occur in a pickup with single gap electrodes (stripline pickup). This phenomenological picture can be used as a guide in pickup design and simulation.
	Poster WEPC26 [0.647 MB]

WEPF01	Alignment of a Nozzle-Skimmer System for a Non Invasive Gas Jet Based Beam Profile Monitor	alignment, laser, electron, ion	803
	V. Tzoganis, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom V. Tzoganis, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: Work supported by EU under contract 215080, Helmholtz Association and GSI under contract VH-BG-328, STFC under the Cockcroft Institute Core Grant No.ST/G008248/1 and a Liverpool - Riken fellowship. A non-invasive gas jet-based beam profile monitor has been developed in the QUASAR Group at the Cockcroft Institute, UK. This shall allow monitoring ultra-low energy, as well as high energy particle beams in a way that causes least disturbance to both, primary beam and accelerator vacuum. In this setup a nozzle-skimmer system is used to generate a thin supersonic curtain-shaped gas jet. However, very small diameters of both, the gas inlet nozzle and subsequent skimmers, required to shape the jet, have caused problems in monitor operation in the past. Here, an image processing based technique is presented which follows after careful manual initial alignment using a laser beam. An algorithm has been implemented in Labview and offers a semi-automated and straightforward solution for all previously encountered alignment issues. The procedure is presented in detail and experimental results are shown.
	Poster WEPF01 [0.863 MB]

WEPF05	An Electron Beam Detector for the FLASH II Beam Dump	radiation, electron, target, laser	814
	F. Perlick, J.D. Good, N. Leuschner, M. Sachwitz DESY Zeuthen, Zeuthen, Germany G. Kube, M. Schmitz, K. Wittenburg, T. Wohlenberg DESY, Hamburg, Germany
	For the electron absorber at FLASH II a detector is developed to control the position, dimensions and profile of the electron beam. Scintillation light, emitted from a luminescent screen in front of the dump window, is reflected by a mirror, located in 2 m distance from the screen, and passes through a vacuum window. Two different optical systems will be installed redundantly for beam image transfer: a conventional lens-mirror-system and a system using a radiation-hard optical fibre bundle. A CCD camera, located in one and a half meter distance from the beam line, is used for the optical analysis. An experimental setup, where the terms of installation of the components correspond to the FLASH accelerator, has been built up in a lab to coordinate the interaction of the screen with the components of the optical system. It was shown that the resolution of the lens-mirror-system is about one line pair per millimeter. An experiment is set up to test the impact of radiation on the optical qualities of the fibre optic bundle by installing it onto a “radioactive hot spot” at the bunch compressor in the FLASH accelerator.
	Poster WEPF05 [1.926 MB]

WEPF06	A Fast Switching Mirror Unit at FLASH	laser, site, DESY, free-electron-laser	818
	F. Perlick, J.D. Good, N. Leuschner, A.S. Ontoso, M. Sachwitz, L.V. Vu DESY Zeuthen, Zeuthen, Germany H. Schulte-Schrepping DESY, Hamburg, Germany
	The Free Electron Laser (FLASH) at DESY Hamburg is a linac providing unique experimental opportunities to investigate the atomic structure and the properties of materials, nanoparticles, viruses and cells. At the experimental hall, the incoming FEL beam can be deflected towards five test sites by silicon mirrors mounted into vacuum vessels, of which one is operated in permanent switching mode, allowing the simultaneous use of the light at two different test sites. So far, the entire vacuum vessel with the mirror inside is moved into the beam by a linear motor. This results in high translatory inertia and, to compensate the vessel motion, requires vacuum bellows, which have a limited lifetime especially at higher switching frequencies. Therefore, in the recent design the mirror is shifted by piezo motors operated inside the vessel under ultra-high vacuum conditions. However, temperature measurements revealed that during continuous operation the motor reaches up to 90°C only when exposed to air, necessitating long breaks to allow it to cool. Therefore suitable cooling methods are being investigated to guarantee continuous operation of the motor under ultra-high vacuum conditions.
	Poster WEPF06 [2.431 MB]

WEPF35	Current Status of the Schottky Cavity Sensor for the CR at FAIR	coupling, dipole, shielding, simulation	907
	M. Hansli, R. Jakoby, A. Penirschke TU Darmstadt, Darmstadt, Germany P. Hülsmann, W. Kaufmann GSI, Darmstadt, Germany
	Funding: This work was supported by the GSI. The author would like to thank the CST AG for providing CST Studio Suite. In this paper the current status of the Schottky Cavity Sensor development for the Collector Ring at FAIR, a dedicated storage ring for secondary particles, rare isotopes, and antiprotons, is presented. Designed for longitudinal and transversal Schottky signals, the Sensor features a pillbox cavity with attached waveguide filters utilizing the Monopole mode at 200 MHz for longitudinal and the Dipole mode at around 330 MHz for transversal Schottky measurements. Separated coupling structures allow for mode-selective coupling to measure the different Schottky planes independently. A ceramic vacuum shielding inside the pillbox is implemented to enable non-hermetic adjustable coupling, tuning devices and waveguide structures. Simulations of the structure with focus on the impact of the coupling structures and the ceramic vacuum shielding on the R-over-Q values and the coupling are presented as well as measurements of a scaled demonstrator including comparisons with the simulations.

Paper

Title

Other Keywords

Page

MOPC02

Status of Beam Diagnostics for NSLS-II Booster

booster, controls, BPM, diagnostics

41

V.V. Smaluk, E.A. Bekhtenev, S.E. Karnaev, G.V. Karpov, O.I. Meshkov
BINP SB RAS, Novosibirsk, Russia
D. Padrazo, O. Singh, V.V. Smaluk, K. Vetter, G.M. Wang
BNL, Upton, Long Island, New York, USA

For the NSLS II third generation light source, a full-energy Booster ring has been designed and produced by Budker Institute of Nuclear Physics. For the Booster commissioning and operation, following beam diagnostic instruments have been designed and manufactured: 6 beam flags, 36 electrostatic pickups with BPM receivers, 2 synchrotron light monitors (SLMs), 1 DC current transformer, 1 fast current transformer, Tune Measurement System (TMS) including 2 strip-line assemblies. All the equipment has been installed in the Booster ring and Injector Service Area. Control software of the beam diagnostic devices has been developed and incorporated into the NSLS-II control system using the EPICS environment. A number of high-level applications has been developed using Control System Studio and Python. The Integrated Testing and the System Level Testing have been performed. Current status of the Booster beam diagnostic instrumentation is reviewed.

MOPF01

Transverse Beam Size Measurements Using Interferometry at ALBA

transverse, synchrotron, dipole, radiation

193

U. Iriso, L. Torino
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
T.M. Mitsuhashi
KEK, Ibaraki, Japan

Double-slit interferometry using visible light has been used for measuring the transverse beam size in different accelerators. The beam size is inferred from the analysis of the spatial coherence of the synchrotron light produced by a bending magnet. At ALBA, this technique has been implemented with moderate success, mainly limited by the present imperfections in the in-vacuum mirror that is used to extract the light out of the vacuum chamber. In this paper, we report the results obtained with the current set-up, and discuss possible improvements.

MOPF05

Operating Semiconductor Timepix Detector with Optical Readout in an Extremely Hostile Environment of Laser Plasma Acceleration Experiment

laser, target, shielding, optics

208

L. Pribyl
Czech Republic Academy of Sciences, Institute of Physics, Prague, Czech Republic

The laser plasma acceleration (LPA) experiments produce very intensive electromagnetic pulses (EMP) complicating operation of sensitive electronic detectors. We present our experience with new optical readout and EMP shielding for hybrid silicon pixel detector Timepix*, which enabled its operation in an extremely hostile electromagnetic LPA environment. The Timepix detector provides a matrix of 256x256 spectroscopic channels with 55 μm pitch. An optical readout, battery powering and shielding against electromagnetic pulses (EMP) have been developed as part of the ELI Beamlines/IEAP project for the detector Timepix and it significantly improved its resistance to EMP with respect to previous setup using metallic cables for both data acquisition and powering. The new optical setup was successfully tested under vacuum at Prague Asterix Laser System (PALS) during experiments with laser pulses of energies up to 700 J and duration of 350 ps bombarding thin foil solid target. Electromagnetic field was measured both outside the vacuum chamber and inside. The recorded spectrometric data were analyzed and interpreted in a context of an independent experimental campaign run in parallel.
* X. Llopart et al.: Timepix, a 65k Programmable Pixel Readout Chip for Arrival Time, Energy and/or Photon Counting Measurements, Nucl. Instr. and Meth. in Phys. Res. A. Vol. 581 (2007), p485

MOPF24

Magnetic Materials for Current Transformers

CERN, impedance, damping, GSI

263

S. Aguilera, P. Odier, R. Ruffieux
CERN, Geneva, Switzerland

At CERN, the circulating beam current measurement is provided by two types of transformers, the Direct Current Current Transformers (DCCT) and the Fast Beam Current Transformers (FBCT). Each type of transformer requires different magnetic characteristics regarding parameters such as permeability, coercivity and shape of the magnetization curve. Each transformer is built based on toroidal cores of a magnetic material which gives these characteristics. For example, DCCTs consist of three cores, two for the measurement of the DC component and one for the AC component. In order to study the effect of changes in these parameters on the current transformers, several interesting raw materials based on their as-cast properties were selected with the annealing process used to tune their properties for the individual needs of each transformer. First annealing tests show that the magnetization curve, and therefore the permeability, of the material can be modified, opening the possibility for building and studying a variety of transformer cores.

Poster MOPF24 [1.185 MB]

MOPF27

A Beam Current Monitor for the VECC Accelerator

linac, gun, diagnostics, radiation

275

W.R. Rawnsley, R.E. Laxdal
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

TRIUMF is building VECC, the first stage of a 50 MeV electron linac. Beam diagnostic devices will be inserted radially into 8-port vacuum boxes. RF shields, 6.3 cm dia. tubes perforated by pump out slots, can be inserted to reduce wakefields. They will also serve as capacitive probes picking up harmonics of the 650 MHz bunch rate. 100 mV P/P was measured for 3 mA at 100 kV. A SC cavity will accelerate the beam to 10 MeV. The dump current is limited by the shielding to 300 W. We will use a 3 mA beam at 1% duty cycle. Two RF shields will monitor the current. A newly developed circuit will give dc outputs proportional to the peak and average current. It uses a log detector with range of 70 dB for 1 dB of error and a rise and fall time of ~20 ns. Terasic development boards process the log signal. It is digitized by a 14-bit ADC at a 50 MHz rate and passed to a FPGA programmed in Verilog. Altera Megafunctions offset, scale, convert to floating point, antilog and filter the signal in a pipeline architecture. Two 14-bit DACs provide the outputs. Digital processing maintains the wide dynamic range. Beam pulses can be <250 ns and the sample rate insures accuracy at low duty cycle.

Poster MOPF27 [1.314 MB]

MOPF29

A Non-Invasive Beam Monitor for Hadron Therapy Beams

proton, CERN, target, LHC

283

T. Cybulski, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
T. Cybulski, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
A. Kacperek, B. Marsland, I. Taylor, A. Wray
The Douglas Cyclotron, The Clatterbridge Cancer Centre NHS Foundation Trust, Wirral, United Kingdom

Funding: Work supported by the EU under contract PITN-GA-2008-215080 and the STFC Cockcroft Institute Core Grant No. ST/G008248/1
Hadron therapy allows for precise dose delivery to the tumour volume only and hence decreases the dose delivered to the nearby organs and healthy tissue. Ideally, the beam would be monitored whilst being delivered to the patient. A novel, real–time and non-interceptive beam monitor for hadron therapy beams has been developed in the QUASAR Group. It is based on the LHCb VErtex LOcator (VELO) detector and couples to the treatment beam’s transverse halo to determine the intensity, position and ultimately the dose of the treatment beam. This contribution presents the design of a stand-alone version of the VELO detector which was developed for the Clatterbridge Cancer Centre (CCC) treatment line. The mechanical and electronic design of the monitor and its data acquisition system are shown, with a focus on the detector positioning and cooling system. Monte Carlo simulations into expected signal distributions are compared against first measurements with the 60 MeV proton beam at CCC.

MOPF31

Design and Performance of the Biased Drift Tube System in the BNL Electron Lens

RHIC, electron, beam-losses, ion

291

T.A. Miller, W. Fischer, D.M. Gassner, X. Gu, A.I. Pikin, S. Polizzo, P. Thieberger
BNL, Upton, Long Island, New York, USA
J. Barth
Barth Electronics, Boulder City, USA

Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy.
The installation of the Electron Lenses in RHIC will be completed this year. Its design includes a series of drift tubes through which the electron beam copropagates, with the RHIC proton beams. These drift tubes are used to create an electric field gradient to sweep out ions that become trapped within the central magnetic field where the electron beam interacts with the proton beams. These isolated drift tubes are biased by high voltage power supplies. Without a path for the proton beam image currents, high voltages will develop on the drift tubes that can be detrimental to the electron beam and increase the RHIC machine impedance. This paper presents the design of the drift tubes, axial electric field gradient, and the custom high voltage RF bias tees that were designed to provide separate paths for the high frequency image currents and the DC high voltage bias over the same cables. The design and simulation of the bias tee is discussed, as well as RF signals from the proton beam current imaged on the drift tubes, as measured through the bias tees during the commissioning of the blue RHIC beam electron lens this past spring.

Poster MOPF31 [31.237 MB]

MOPF34

Nuclotron Deuterons Beam Parameters Measurements Using SSNTD

target, dipole, quadrupole, synchrotron

299

K.V. Husak, V.V. Bukhal
The Joint Institute of Power and Nuclear Reserach - "SOSNY" NASB, Minsk, Belarus
M. Artiushenko, V.V. Sotnikov, V.A. Voronko
NSC/KIPT, Kharkov, Ukraine
A.A. Patapenka, A.A. Safronava, I.V. Zhuk
JIPNR-Sosny NASB, Minsk, Belarus

ADS are considered as prospective nuclear installations for energy production and nuclear waste transmutation or recycling. The international project “Energy and Transmutation Radioactive Wastes” running in the Laboratory of High Energy Physics at JINR (Dubna, Russia) at the accelerator complex “Nuclotron” is aimed at a feasibility study of using a deeply subcritical natural or depleted uranium or thorium active core with very hard neutron spectrum inside for effective burning of the core material together with spent nuclear fuel. For any ADS experiment a necessary and a key element is beam diagnostics. In this paper a technique for precise measurement of deuteron beam parameters using SSNTD, developed within the bounds of “E&T RAW” project, is presented. The deuteron beam parameters, specifically beam shape, size and position on a target, are obtained from track density distribution on the irradiated track detectors. The presented technique has a resolution of 1 mm. The experimental results of beam parameter measurements for deuterons with energies of 2, 4 and 8 GeV at the irradiation of the uranium subcritical assembly “QUINTA”, obtained with the SSNTD technique, are presented.

Poster MOPF34 [0.826 MB]

TUPC07

Design and Impedance Optimization of the SIRIUS BPM Button

BPM, impedance, storage-ring, longitudinal

365

H.O.C. Duarte, S.R. Marques, L. Sanfelici
LNLS, Campinas, Brazil

Design of several BPM Buttons is presented with detail impedance, heat transfer and mechanical analysis. Special attention is given to the application of ceramics as materials with low relative permittivity inside of the BPM Button and to the geometric shape of the BPM Button. The heat dissipation is evaluated based on the loss factor calculated for a 2.65mm bunch length. The narrow-band impedance is discussed and its dependence on applied ceramic materials is compared.

Poster TUPC07 [1.715 MB]

TUPC11

Beam-Based Measurement of ID Taper Impedance at Diamond

impedance, transverse, simulation, BPM

380

V.V. Smaluk, R. Bartolini, R.T. Fielder, G. Rehm
Diamond, Oxfordshire, United Kingdom

New insertion devices (IDs) are being designed now for a Diamond upgrade. One of the important topics of the design is the coupling impedance of the ID vacuum chamber movable tapers. To get a complete and reliable information of the impedance, analytical estimations, numerical simulation and beam-based measurement have been performed. The impedance of an existing ID taper geometrically similar to the new one has been measured using the orbit bump method. It turns out that in spite of the small magnitude (a few um) of orbit distortion to be observed in this case, the BPM resolution is sufficient for this measurement. The measurement results in comparison with simulation data are discussed in this paper.

TUPC37

Presentation of the Smith-Purcell Experiment at SOLEIL

radiation, SOLEIL, linac, longitudinal

460

N. Delerue, J. Barros, S. Jenzer, M. Vieille Grosjean
LAL, Orsay, France
L. Cassinari, M. Labat
SOLEIL, Gif-sur-Yvette, France
G. Doucas, I.V. Konoplev, A. Reichold
JAI, Oxford, United Kingdom
A. Faus-Golfe, N. Fuster Martinez, J. Resta-López
IFIC, Valencia, Spain

Funding: Work supported by seed funding from Université Paris-Sud, program 'Attractivité' and by the French ANR under contract ANR-12-JS05-0003-01.
The potential of Coherent Smith-Purcell radiation as a longitudinal bunch profile monitor has already been demonstrated and has recently been extended to the sub-picosecond range. As a critical step toward the construction of a single shot bunch profile monitor using Coherent Smith-Purcell radiation it is important to measure very accurately the distribution of such radiation. Optimum background suppression techniques need to be found and relatively cheap detectors suitable for the far infra-red need to be qualified. To perform these tasks a test stand has been installed at the end of the linac of the synchrotron SOLEIL. This test stand and the first results from its commissioning will be presented here.

TUPF25

Beam Current Measurement System in CSNS LINAC

linac, beam-transport, SNR, instrumentation

565

P. Li, F. Li, M. Meng, T.G. Xu
IHEP, Beijing, People's Republic of China

The China Spallation Neutron Source is being constructed at Dongguan, Guangdogn province. Before RCS Ring there are three beam transport sections in CSNS LINAC : LEBT, MEBT, LRBT, where various beam measurement monitors will be installed. Beam Current Transformers (BCTs) have been designed to measure beam macro-pulse current that will operate between 5mA to 80mA . The BCTs have the same inductance but different size in these three sections. Besides, beam parameters should be monitored also between the DTL four parts. There is no BCT but a FCT would be installed after DTL1 due to space limit. So this FCT is planned to measure the macro-pulse current, and we have to proceed the acquired data to show the original macro-pulse waveform due to the FCT’s low inductance.

Poster TUPF25 [0.736 MB]

TUPF36

Analysis of Modulation Signals Generated in the TE Wave Detection Method For Electron Cloud Measurements

electron, resonance, BPM, pick-up

605

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

Funding: Work supported by the U.S. Department of Energy and by the US National Science Foundation under Contracts No. DE-AC02-05CH11231, DE-FC02-08ER41538, DE-SC0006505, PHY-0734867, PHY-1002467.
The evaluation of the electron cloud density in storage rings by measuring its effects on the transmission of electromagnetic signals across portions of the beampipe is a widely used technique and the most suited for measurements over extended regions. Recent results show that in a majority of cases the RF signal transmission takes place by coupling to standing waves excited in the vacuum chamber. In such a case the effect of a varying cloud density is a simultaneous amplitude, phase and frequency modulation of a fixed frequency drive signal. The characteristics of the modulation depend not only on the cloud density values and spatial distribution, but also on its temporal evolution and on the damping time of the standing waves. In this paper we evaluate the relationship between measured modulation sidebands amplitude and the electron cloud density when cloud and electromagnetic resonance rise and fall times are of the same order of magnitude, as it is the case in the accelerators where we have conducted our experiments.

WEAL2

Extremely Low Emittance Beam Size Diagnostics with Sub-Micrometer Resolution Using Optical Transition Radiation

OTR, laser, electron, transverse

615

K.O. Kruchinin, S.T. Boogert, P. Karataev, L.J. Nevay
Royal Holloway, University of London, Surrey, United Kingdom
A.S. Aryshev, M.V. Shevelev, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan
B. Bolzon
The University of Liverpool, Liverpool, United Kingdom
B. Bolzon, T. Lefèvre, S. Mazzoni
CERN, Geneva, Switzerland

Transverse electron beam diagnostics is crucial for stable and reliable operation of the future electron-positron linear colliders such as CLIC or Higgs Factory. The-state-of-the-art in transverse beam diagnostics is based on the laser-wire technology. However, it requires a high power laser significantly increases the cost of the laser-wire system. Therefore, a simpler and relatively inexpensive method is required. A beam profile monitor based on Optical Transition Radiation (OTR) is very promising. The resolution of conventional OTR monitor is defined by a root-mean-square of the so-called Point Spread Function (PSF). In optical wavelength range the resolution is diffraction limited down to a few micrometers. However, in * we demonstrated that the OTR PSF has a structure which visibility can be used to monitor vertical beam size with sub-micrometer resolution. In this report we shall represent the recent experimental results of a micron-scale beam size measurement. We shall describe the entire method including calibration procedure, new analysis, and calculation of uncertainties. We shall discuss the hardware status and future plans.
* P. Karataev et al., Physical Review Letters 107, 174801 (2011).

Slides WEAL2 [5.120 MB]

WECL2

Radiation Damages and Characterization in the SOLEIL Storage Ring

radiation, quadrupole, dipole, SOLEIL

644

N. Hubert, P. Brunelle, N. Béchu, L. Cassinari, C. Herbeaux, S. Hustache, J.-F. Lamarre, P. Lebasque, F. Marteau, A. Nadji, L.S. Nadolski
SOLEIL, Gif-sur-Yvette, France

After six years of operation, equipment located close to some vacuum chambers of the SOLEIL storage ring show unexpected damages due to radiation. It has been pointed out that, inside the so called “quadrupole” vacuum chambers, fluorescence X-rays are emitted by the materials that intercept upstream dipole synchrotron radiation. The energy of the emitted X-ray is too high to be significantly attenuated by the aluminum of which the vacuum chamber is made. Diagnostics and means used to characterize this radiation are presented, and measurements are compared to calculations.

Slides WECL2 [2.336 MB]

WEPC03

Brookhaven 200 MeV Linear Accelerator Beam Instrumentation Upgrade

linac, instrumentation, diagnostics, radiation

656

O. Gould, B. Briscoe, D.M. Gassner, V. LoDestro, R.J. Michnoff, J. Morris, D. Raparia, K. Sanders, W. Shaffer, C. Theisen, M. Wilinski
BNL, Upton, Long Island, New York, USA
D. Persaud
City College of The City University of New York, New York, USA

The Brookhaven National Laboratory 200 MeV H⁻ LINAC beam instrumentation equipment has been in operation for four decades with various changes implemented over this period. There is a need to upgrade the entire beam instrumentation system of the LINAC to improve the diagnostics of the beam from the Low Energy Beam Transport Line through the LINAC and into the LINAC Booster Transfer Line and BLIP line. Profile Monitors, Current Monitors, Beam Position Monitors, Loss Radiation Monitors, and Emittance Measurement devices are to be designed and implemented over the next three years. This upgrade will improve the operation reliability, beam quality and beam losses. Additional improvements will be obtained by designing the beam instrumentation system to integrate with other proposed diagnostics and malfunction detection and display upgrades in the LINAC Control Room to improve the overall performance of the LINAC.

Poster WEPC03 [18.356 MB]

WEPC09

Performance of NSLS2 Button BPM

BPM, simulation, storage-ring, booster

678

W.X. Cheng, B. Bacha, B.N. Kosciuk, S. Krinsky, O. Singh
BNL, Upton, Long Island, New York, USA

Several types of button BPMs are used in NSLS2 complex. Coaxial vacuum feedthroughs are used to couple the beam induced signal out. The feedthroughs are designed to match the external transmission line and electronics with characteristic impedance of 50 Ohm. Performances of these BPM feedthroughs are presented in this paper.

WEPC26

Pickup Electrode Electrodynamics Investigation

pick-up, LEFT, transverse, impedance

742

A. Kalinin
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Waves induced in a pickup by beam were investigated on a large scale model, using 10ps step in coaxial line as beam, and a differentiating capacitive probe. The probe signal was observed at 20GHz oscilloscope. In each of the front and rear transverse gaps between pickup electrode and wall (button pickup), a shorter-than-gap bunch excites a ‘plain-wave’ packet which length is of the order of gap length over c. Two packets are spaced by electrode length over c. The packets propagate along the electrode to a coaxial connector. At this low impedance common point each of the packets partially reflects back and partially passes into the opposite gap. The voltage appearing on the impedance excites two TEM-wave packets: one propagates backwards, another one propagates forward through connector. The connector output is sum of two such packets spaced the same as two incident packets. The packets propagating backwards reflect from the electrode open end, come back to the summing point and generate output in similar way. The same processes occur in a pickup with single gap electrodes (stripline pickup). This phenomenological picture can be used as a guide in pickup design and simulation.

Poster WEPC26 [0.647 MB]

WEPF01

Alignment of a Nozzle-Skimmer System for a Non Invasive Gas Jet Based Beam Profile Monitor

alignment, laser, electron, ion

803

V. Tzoganis, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
V. Tzoganis, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: Work supported by EU under contract 215080, Helmholtz Association and GSI under contract VH-BG-328, STFC under the Cockcroft Institute Core Grant No.ST/G008248/1 and a Liverpool - Riken fellowship.
A non-invasive gas jet-based beam profile monitor has been developed in the QUASAR Group at the Cockcroft Institute, UK. This shall allow monitoring ultra-low energy, as well as high energy particle beams in a way that causes least disturbance to both, primary beam and accelerator vacuum. In this setup a nozzle-skimmer system is used to generate a thin supersonic curtain-shaped gas jet. However, very small diameters of both, the gas inlet nozzle and subsequent skimmers, required to shape the jet, have caused problems in monitor operation in the past. Here, an image processing based technique is presented which follows after careful manual initial alignment using a laser beam. An algorithm has been implemented in Labview and offers a semi-automated and straightforward solution for all previously encountered alignment issues. The procedure is presented in detail and experimental results are shown.

Poster WEPF01 [0.863 MB]

WEPF05

An Electron Beam Detector for the FLASH II Beam Dump

radiation, electron, target, laser

814

F. Perlick, J.D. Good, N. Leuschner, M. Sachwitz
DESY Zeuthen, Zeuthen, Germany
G. Kube, M. Schmitz, K. Wittenburg, T. Wohlenberg
DESY, Hamburg, Germany

For the electron absorber at FLASH II a detector is developed to control the position, dimensions and profile of the electron beam. Scintillation light, emitted from a luminescent screen in front of the dump window, is reflected by a mirror, located in 2 m distance from the screen, and passes through a vacuum window. Two different optical systems will be installed redundantly for beam image transfer: a conventional lens-mirror-system and a system using a radiation-hard optical fibre bundle. A CCD camera, located in one and a half meter distance from the beam line, is used for the optical analysis. An experimental setup, where the terms of installation of the components correspond to the FLASH accelerator, has been built up in a lab to coordinate the interaction of the screen with the components of the optical system. It was shown that the resolution of the lens-mirror-system is about one line pair per millimeter. An experiment is set up to test the impact of radiation on the optical qualities of the fibre optic bundle by installing it onto a “radioactive hot spot” at the bunch compressor in the FLASH accelerator.

Poster WEPF05 [1.926 MB]

WEPF06

A Fast Switching Mirror Unit at FLASH

laser, site, DESY, free-electron-laser

818

F. Perlick, J.D. Good, N. Leuschner, A.S. Ontoso, M. Sachwitz, L.V. Vu
DESY Zeuthen, Zeuthen, Germany
H. Schulte-Schrepping
DESY, Hamburg, Germany

The Free Electron Laser (FLASH) at DESY Hamburg is a linac providing unique experimental opportunities to investigate the atomic structure and the properties of materials, nanoparticles, viruses and cells. At the experimental hall, the incoming FEL beam can be deflected towards five test sites by silicon mirrors mounted into vacuum vessels, of which one is operated in permanent switching mode, allowing the simultaneous use of the light at two different test sites. So far, the entire vacuum vessel with the mirror inside is moved into the beam by a linear motor. This results in high translatory inertia and, to compensate the vessel motion, requires vacuum bellows, which have a limited lifetime especially at higher switching frequencies. Therefore, in the recent design the mirror is shifted by piezo motors operated inside the vessel under ultra-high vacuum conditions. However, temperature measurements revealed that during continuous operation the motor reaches up to 90°C only when exposed to air, necessitating long breaks to allow it to cool. Therefore suitable cooling methods are being investigated to guarantee continuous operation of the motor under ultra-high vacuum conditions.

Poster WEPF06 [2.431 MB]

WEPF35

Current Status of the Schottky Cavity Sensor for the CR at FAIR

coupling, dipole, shielding, simulation

907

M. Hansli, R. Jakoby, A. Penirschke
TU Darmstadt, Darmstadt, Germany
P. Hülsmann, W. Kaufmann
GSI, Darmstadt, Germany

Funding: This work was supported by the GSI. The author would like to thank the CST AG for providing CST Studio Suite.
In this paper the current status of the Schottky Cavity Sensor development for the Collector Ring at FAIR, a dedicated storage ring for secondary particles, rare isotopes, and antiprotons, is presented. Designed for longitudinal and transversal Schottky signals, the Sensor features a pillbox cavity with attached waveguide filters utilizing the Monopole mode at 200 MHz for longitudinal and the Dipole mode at around 330 MHz for transversal Schottky measurements. Separated coupling structures allow for mode-selective coupling to measure the different Schottky planes independently. A ceramic vacuum shielding inside the pillbox is implemented to enable non-hermetic adjustable coupling, tuning devices and waveguide structures. Simulations of the structure with focus on the impact of the coupling structures and the ceramic vacuum shielding on the R-over-Q values and the coupling are presented as well as measurements of a scaled demonstrator including comparisons with the simulations.