Keyword: BPM
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MOPC02 Status of Beam Diagnostics for NSLS-II Booster booster, controls, vacuum, 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.  
 
MOPC06 Beam Diagnostics System for a Photo-Neutron Source Driven by 15MeV Electron Linac electron, beam-position, linac, diagnostics 57
 
  • Y.B. Yan, J. Chen, Z.C. Chen, Y.B. Leng, L.Y. Yu, R.X. Yuan, W.M. Zhou
    SINAP, Shanghai, People's Republic of China
  
  A photo-neutron source driven by 15MeV electron LINAC is under construction at Shanghai Institute of Applied Physics (SINAP). Several kinds of beam monitors (BPM, Profile and ICT) have been installed. The stripline beam position monitor with eight electrodes was designed, also for energy spread measurement. Due to the multi-bunch operation mode, a custom RF front end was adopted, which down-converts the signal from 2856MHz to 500MHz and then brings it to Libera Single Pass E. The beam position monitor was based on the integrated step-servo motor and GigE Vision camera. For the beam charge measurement we used the ICT from Bergoz and scope from Agilent. The detail of the whole beam diagnostics system development will be reported in this paper.  
 
MOPC09 Development of the Sirius RF BPM Electronics controls, storage-ring, pick-up, simulation 63
 
  • D.O. Tavares, R.A. Baron, F.H. Cardoso, S.R. Marques, J.L.B. Neto, L.M. Russo
    LNLS, Campinas, Brazil
  • A.P. Byszuk, G. Kasprowicz, A.J. Wojenski
    Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
  
  A BPM system has been developed for the new low emmitance 3 GeV Brazilian synchrotron light source, Sirius. The Sirius BPM electronics is a modular system based on a PICMG(R) MicroTCA.4 platform using ADC mezzanine cards in ANSI/VITA 57.1 FMC form factor and standalone RF front-end boards. It has been designed under the CERN Open Hardware License (OHL) in a collaboration between Brazilian Synchrotron Light Laboratory (LNLS) and Warsaw University of Technology (WUT). This paper presents: i) overall architecture of the BPM system; ii) performance evaluation of the first prototype of the BPM electronics comprehending beam current, filling pattern and temperature dependencies as well as resolution vs. beam current; and iii) preliminary results with beam at LNLS's UVX storage ring.  
poster icon Poster MOPC09 [1.451 MB]  
 
MOPC12 Development of the New Electronic Instrumentation for the LIPAc/IFMIF Beam Position Monitors diagnostics, beam-position, instrumentation, controls 71
 
  • A. Guirao, D. Jimenez, L.M. Martinez Fresno, J. Molla, I. Podadera
    CIEMAT, Madrid, Spain
  
  Funding: Work partially supported by the Spanish Ministry of Science and Innovation under project AIC10-A-000441 and AIC-A-2011-0654.
Among all the LIPAc/IFMIF accelerator diagnostics instrumentation, the Beam Position Monitors are a cornerstone for its operation. A new approach for the LIPAc/IFMIF beam position monitors acquisition electronics is proposed for the twenty BPM stations distributed along the accelerator. The new system under development is a fully digital instrumentation which incorporates automatic calibration of the monitors' signals and allows monitoring of both fundamental and second signal harmonics. The current state of the development and first experimental results of the system on the test bench will be presented. 		 
 
MOPC13 Design of Cold Beam Position Monitor for CADS Injector II Proton LINAC linac, cryogenics, proton, alignment 75
 
  • Y. Zhang, X.C. Kang, M. Li, J.X. Wu, G. Zhu
    IMP, Lanzhou, People's Republic of China
  
  Cold beam position monitor based on capacitive buttons are designed for Chinese Accelerator Driven System (CADS) Injector II proton LINAC. This LINAC is aiming to produce a maximum design current of 15 mA at the 10 MeV energy with an operating frequency of 162.5 MHz. Cold button BPM will be installed in the Cryomodule, which will be in the middle of the superconductor cavity and the superconductor magnet. Some special issues must be considered when designing a cold BPM: low-beta beam in the cryogenic environment, strong rf-field from the superconductor cavity and high magnetic field from the superconductor magnet. In this contribution, the status of cold BPM will be presented, focusing on the electromagnetic response for low-beta beams and mechanical design in the cryogenic environment.  
 
MOPC14 Beam Position Monitors R&D for keV Ion Beams simulation, pick-up, antiproton, multipole 78
 
  • S. Naveed, A.A. Nosych, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • S. Naveed, A.A. Nosych, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • A.A. Nosych, L. Søby
    CERN, Geneva, Switzerland
  
  Funding: Work supported by the EU within the DITANET and oPAC projects under contracts 215080 and 289485, HGF and GSI under contract VH-NG-328 and STFC under the Cockcroft Institute core grant ST/G008248/1.
Beams of cooled antiprotons at keV energies shall be provided by the Ultra-low energy Storage Ring (USR) at the Facility for Low energy Antiproton and Ion Research (FLAIR) and the Extra Low ENergy Antiproton ring (ELENA) at CERN's Antiproton Decelerator (AD) facility. Both storage rings put challenging demands on the beam position monitoring system as their capacitive pick-ups should be capable of determining the beam position of beams at low intensities and low velocities, close to the noise level of state-of-the-art electronics. In this contribution we describe the design and anticipated performance of BPMs for low-energy ion beams on the examples of the USR and ELENA orbit measurement systems. We also present the particular challenges encountered in the numerical simulation of pickup response at very low beta values and describe an experimental setup realized at the Cockcroft Institute for BPM callibration. Finally, we provide an outlook on how the implementation of faster algorithms for the simulation of BPM characteristics could potentially help speed up such studies considerably. 		 
 
MOPC16 FPGA Based Fast Orbit Feedback Data Acquisition System for Electron and Hadron Storage Rings feedback, hadron, COSY, storage-ring 82
 
  • G. Schünemann, P. Hartmann, D. Schirmer, G. Schmidt, P. Towalski, T. Weis
    DELTA, Dortmund, Germany
  
  In the course of a BMBF supported development of a fast orbit feedback system for electron and hadron storage rings, in prospect of the upcoming FAIR facility, this paper presents the developed data acquisition system, based on Field Programmable Gateway Array (FPGA) technology, as well as the first results of in-situ measurements. Data was successfully taken at the TU-Dortmunds synchrotron light source DELTA as well as hadron storage rings COSY of the Forschungszentrum Jülich (FZJ) and SIS18 of the GSI Helmholtzzentrum für Schwerionenforschung GmbH (GSI).  
 
MOPC17 Calibration of a Non-Linear Beam Position Monitor Electronics by Switching Electrode Signals beam-position, LHC, SPS, CERN 85
 
  • M. Gasior
    CERN, Geneva, Switzerland
  
  Button electrode signals from beam position monitors embedded into new LHC collimators will be individually processed with front-end electronics based on compensated diode detectors and digitized with 24-bit audio-range ADCs. This scheme allows sub-micrometre beam orbit resolution to be achieved with simple hardware and no external timing. As the diode detectors only operate in a linear regime with large amplitude signals, offset errors of the electronics cannot be calibrated in the classical way with no input. This paper describes the algorithms developed to calibrate the offset and gain asymmetry of these nonlinear electronic channels. Presented algorithm application examples are based on measurements performed with prototype diode orbit systems installed on the CERN SPS and LHC machines.  
 
MOPC19 Status of the Beam Position Monitors for LIPAc pick-up, simulation, beam-position, linac 93
 
  • I. Podadera, F.M. De Aragon, A. Guirao, D. Jimenez, A. Lara, L.M. Martinez, J. Molla
    CIEMAT, Madrid, Spain
  
  Funding: Work partially supported by the Spanish Ministry of Science and Innovation under project AIC10-A-000441 and AIC-A-2011-0654.
The LIPAc accelerator will be a 9 MeV, 125 mA CW deuteron accelerator which aims to validate the technology that will be used in the future IFMIF accelerator. Several types of Beam Position Monitors –BPM’s- are placed in each section of the accelerator to ensure a good beam transport and minimize beam losses. Prototypes of almost all the BPM’s have been already fabricated. Acceptance tests have been carried out on each device. The output of the vacuum leak tests and electrical tests will be analyzed in this contribution. In addition, the test bench to characterize the BPM’s has been upgraded and validated using some prototypes in order to obtain a better global measurement accuracy of the electrical center offset. The test bench can be used to crosscheck the simulations with the real response of each BPM. The result of the comparison will be discussed in detail. 		 
 
MOPC20 Application of Metal-Semiconductor-Metal (MSM) Photodetectors for Transverse and Longitudinal Intra-Bunch Beam Diagnostics synchrotron, CTF3, CERN, diagnostics 97
 
  • R.J. Steinhagen
    CERN, Geneva, Switzerland
  • M.J. Boland
    SLSA, Clayton, Australia
  • T.G. Lucas, R.P. Rassool
    The University of Melbourne, Melbourne, Australia
  • T.M. Mitsuhashi
    KEK, Ibaraki, Japan
  
  The performance reach of modern accelerators is often governed by the ability to reliably measure and control the beam stability. In high-brightness lepton and high-energy hadron accelerators the use of optical diagnostic techniques for this purpose is becoming more widespread as the required bandwidth, resolution and high RF beam power level involved limit the use of traditional electro-magnetic RF pick-up based methods. This contribution discusses the use of fibre-coupled ultra-fast Metal-Semiconductor-Metal Photodetectors (MSM-PD) as an alternative, dependable means to measure signals deriving from electro-optical and synchrotron-light based diagnostics systems. It describes the beam studies performed at CERN's CLIC Test Facility (CTF3) and the Australian Synchrotron to assess the feasibility of this technology as a robust, wide-band and sensitive technique for measuring transverse intra-bunch and bunch-by-bunch beam oscillations, longitudinal beam profiles, un-bunched beam population and beam-halo profiles. The used amplification schemes, achieved sensitivities, linearity, and dynamic range of the detector setup are presented.  
poster icon Poster MOPC20 [3.065 MB]  
 
MOPC21 Layout of the BPM System for p-LINAC at FAIR and the Digital Methods for Beam Position and Phase Monitoring beam-position, linac, proton, single-bunch 101
 
  • M.H. Almalki, G. Clemente, P. Forck, L. Groening, W. Kaufmann, P. Kowina, C. Krüger, R. Singh
    GSI, Darmstadt, Germany
  • W. Ackermann
    TEMF, TU Darmstadt, Darmstadt, Germany
  • M.H. Almalki
    IAP, Frankfurt am Main, Germany
  • M.H. Almalki
    KACST, Riyadh, Kingdom of Saudi Arabia
  • B.B. Baricevic, R. Hrovatin, P.L. Lemut, M. Znidarcic
    I-Tech, Solkan, Slovenia
  • C.S. Simon
    CEA/DSM/IRFU, France
  
  The planned Proton LINAC at the FAIR facility will provide a beam current from 35 to 70 mA accelerated to 70 MeV by novel CH-type DTLs. Four-fold button Beam Position Monitor (BPM) will be installed at 14 locations along the LINAC and some of these BPMs are mounted only about 40 mm upstream of the CH cavities. The coupling of the RF accelerating field to the BPMs installed close to the CH cavities was numerically investigated. For the digital signal processing using I/Q demodulation a 'Libera Single Pass H' is foreseen. The properties of this digitization and processing scheme were characterized by detailed lab-based tests. Moreover, the performance was investigated by a 80 μA Ne4+ beam at 1.4 MeV / u and compared to a time-domain approach and successive FFT calculation. In particular, concerning the phase determination significant deviations between the methods were observed and further investigations to understand the reason are ongoing.  
poster icon Poster MOPC21 [1.622 MB]  
 
MOPC22 A New High-Dynamic Range BPM for ELBE with Integrated Differential Current Monitor (DCM) ELBE, electron, single-bunch, FEL 104
 
  • A. Büchner, B. Lange
    HZDR, Dresden, Germany
  
  ELBE is a LINAC electron accelerator for small energies (12 to 50 MeV). It serves as a beam source for many quite different experiments. The recent ELBE upgrade allows electron beams with bunches in the range of single electrons to 1 nC. The maximum beam current is 1.6 mA CW and the repetition rates covering the range from one shot single bunch pulses to 26 MHz CW. The existing BPMs and especially the DCMs which are used for the Machine Protection System cannot handle this wide parameter range. To improve this situation the development of new BPMs / DCMs was necessary. The DCMs measure the difference of the beam current between two stripline sensors and produce an interlock for differences greater 10 microamps. The new BPM electronics system has been designed including the DCM functionality because both BPMs and DCMs use the same stripline sensor signals at 1.3 GHz.  
 
MOPC24 Design Of The Stripline BPM For The Advanced Photoinjector Experiment impedance, simulation, coupling, diagnostics 108
 
  • S. De Santis, M.J. Chin, D. Filippetto, W.E. Norum, Z. Paret, G.J. Portmann, F. Sannibale, R.P. Wells
    LBNL, Berkeley, California, USA
  
  Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231
We describe the design, bench testing, and initial commissioning of the shorted striplines beam position monitors used in the Advanced Photoinjector Experiment (APEX) at Lawrence Berkeley National Laboratory. Our BPM's are characterized by extreme compactness, being designed to fit in the vacuum chamber of the quadrupole magnets, with only a short portion including the RF feedthroughs occupying additional beam pipe length. In this paper we illustrate the design process, which included extensive 3D computer simulations, the bench testing of prototype and final components, and the first measurements with beam. The readout electronics is also described. 		 
 
MOPC25 About BPMS to be Used for PAL-XFEL pick-up, XFEL, electron, beam-position 112
 
  • H. J. Choi, H.-S. Kang, C. Kim, S.H. Kim, S.J. Lee, S.J. Park, H. Yang
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  Pohang Accelerator Laboratory (PAL) has been building the X-Ray Free Electron Laser (XFEL), a fourth-generation accelerator, and the construction will be complete in 2015. To successfully construct the XFEL, PAL built an injection test facility (ITF) in 2012, and the facility is in operation. The ITF examines the efficiency of various diagnostic units through extended tests. A BPM is a diagnostic unit that measures the position of an electron bunch. There are various kinds of BPM, and they have different merits and demerits. A user can select any kind of BPM that is appropriate for their purpose, and install it after going through various design and production processes. In order to measure the position of an electron bunch, a cavity BPM is installed at an undulator of PAL-XFEL and a stripline BPM is installed at an accelerator. The efficiency of the stripline BPM was tested at the ITF. The X-band cavity BPM was produced and is being tested at the ITF. This paper aims to introduce the specification and properties of the cavity BPM and stripline BPM to be installed at PAL-XFEL, and explain the physical concept and the way of measuring necessary for designing a stripline pickup.  
 
MOPC29 Realization of Transverse Feedback System for SIS18/100 using FPGA feedback, transverse, controls, FIR 128
 
  • T. Rueckelt
    Technische Universität Darmstadt (TU Darmstadt), Signal Processing Group, Darmstadt, Germany
  • M. Alhumaidi, T. Rueckelt, A.M. Zoubir
    TU Darmstadt, Darmstadt, Germany
  
  Higher beam intensities in particle accelerator are usually prevented by beam instabilities. To cure these instabilities, additional active system must be used besides passive damping. For this purpose, we have developed a distributed low-latency Transverse Feedback System (TFS) using FPGAs. Data acquisition takes place on multiple BPMs with individual FPGAs and ADCs around the accelerator ring. Acquired data is compressed and sent over broadband fiber optic wires to a central unit. For synchronization, data is tagged using timestamps from a reference time, which is distributed by a specially constrained network time protocol to obtain cycle accuracy. The central unit provides an FIR filter for system bandwidth limitation, and an adaptive IIR filter for stable beam signal rejection. Feedback is given using a linear combination of the pre-processed BPM signals. The system provides substantial flexibility, due to the possibility to configure most parameters online. Filters, feedback sources and parameters, compression rate and more can be adapted via Ethernet interface, which also supplies analysis data. First results are shown.  
poster icon Poster MOPC29 [1.842 MB]  
 
MOPF26 New Booster Tune Measurement System for TLS and TPS Prototype booster, synchrotron, kicker, beam-losses 271
 
  • P.C. Chiu, J. Chen, Y.-S. Cheng, K.T. Hsu, S.Y. Hsu, K.H. Hu, C.H. Kuo
    NSRRC, Hsinchu, Taiwan
  
  Taiwan Light Source (TLS) is a 1.5 GeV synchrotron based light source and its booster synchrotron was delivered in 1992. Initial booster tune measurement which adopted extraction kicker as beam excitation and use digital oscillator to extract tune was obsolete. Recently, the beam excitation device has been modified to provide more effective excitation strength and new BPM electronics is adopted to acquire tune for routine booster tune measurement. It also provides a chance to experience for the TPS project booster prototype with the similar infrastructure. Efforts will be summarized in the report.  
 
MOPF28 Optics Non-Linear Components Measurement Using BPM Signals optics, focusing, beam-losses, synchrotron 279
 
  • M. Alhumaidi, A.M. Zoubir
    TU Darmstadt, Darmstadt, Germany
  
  The knowledge of linear and non-linear errors in circular accelerator optics is very crucial for controlling and compensating resonances and their consequent beam losses. This is indispensable, especially for high intensity machines. Fortunately, the relationship between the recorded beam offset signals at the BPMs is a manifestation of the accelerator optics, and can therefore be exploited in the determination of the optics linear and non-linear components. We propose a novel method for estimating lattice non-linear components located in-between the positions of two BPMs by analyzing the beam offset signals of a BPMs triple containing these two BPMs. Depending on the non-linear components in-between the locations of the BPMs triple, the relationship between the beam offsets follows a multivariate polynomial. After calculating the covariance matrix of the polynomial terms, the Generalized Total Least Squares method is used to find the model parameters, and thus the non-linear components. Finally, a bootstrap technique is used to determine confidence intervals of the estimated values. Results for synthetic data are shown.  
 
MOPF32 Development of Gated Turn-by-Turn Position Monitor System for the Optics Measurement During Collision of SuperKEKB betatron, controls, optics, coupling 295
 
  • M. Tobiyama, H. Fukuma, H. Ishii, K. Mori
    KEK, Ibaraki, Japan
  
  Gated turn-by-turn monitor system to measure optics functions using non-colliding bunch has been developed for SuperKEKB accelerators. With the fast, glitch cancelling beam switch, beam position of the target bunch will be measured without affecting the fine COD measurement using narrow-band detectors. The gate timing and the bunch position detection are controlled by the Spartan-6 FPGA. The performance of the system, such as the gate timing jitter, data transfer speed from the system to EPICS IOC and the noise effect to the downstream narrow-band detector are reported.  
poster icon Poster MOPF32 [1.531 MB]  
 
TUBL1 NSLS-II BPM and Fast Orbit Feedback System Design and Implementation feedback, storage-ring, controls, linac 316
 
  • O. Singh, B. Bacha, A. Blednykh, W.X. Cheng, J.H. De Long, A.J. Della Penna, K. Ha, Y. Hu, B.N. Kosciuk, M.A. Maggipinto, J. Mead, D. Padrazo, I. Pinayev, Y. Tian, K. Vetter, L.-H. Yu
    BNL, Upton, Long Island, New York, USA
  
  The National Synchrotron Light Source II is a third generation light source under construction at Brookhaven National Laboratory. The project includes a highly optimized, ultra-low emittance, 3 GeV electron storage ring, linac pre-injector and full energy booster synchrotron. The low emittance requires high performance beam position monitor systems, providing measurement to better than 200 nm resolution; and fast orbit feedback systems, holding orbit to similar level of orbit deviations. The NSLS-II storage ring has 30 cells, each deploying up to 8 RF BPMs and 3 fast weak correctors. Each cell consists of a "cell controller", providing fast orbit feedback system infrastructure. This paper will provide a description of system design and summarize the implementation and status for these systems.  
slides icon Slides TUBL1 [5.225 MB]  
 
TUPC06 Status of Beam Diagnostic Systems for TRIUMF Electron Linac diagnostics, target, electron, linac 361
 
  • V.A. Verzilov, P.S. Birney, D.P. Cameron, P. Dirksen, J.V. Holek, S.Y. Kajioka, S. Kellogg, M. Lenckowski, M. Minato, W.R. Rawnsley
    TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
  • J.M. Abernathy, D. Karlen, D.W. Storey
    Victoria University, Victoria, B.C., Canada
  
  TRIUMF laboratory is currently in a phase of the construction of a superconducting 50 MeV 10 mA cw electron LINAC to drive photo-fission based rare radioactive isotope beam (RIB) production. The project imposes certain technical challenges on various accelerator systems including beam diagnostics. In the first place these are a high beam power and strongly varying operating modes ranging from microsecond beam pulses to the cw regime. Diagnostics development interleaves with the construction of the diagnostics instrumentation required for the test facility which delivered the first beam in Fall of 2011. The paper reports the present status of various diagnostics systems along with measurement results obtained at the test facility.  
 
TUPC07 Design and Impedance Optimization of the SIRIUS BPM Button vacuum, 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 icon Poster TUPC07 [1.715 MB]  
 
TUPC11 Beam-Based Measurement of ID Taper Impedance at Diamond impedance, transverse, vacuum, simulation 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.  
 
TUPC12 Status of the Stripline Beam Position Monitor Development for the CLIC Drive Beam CLIC, beam-position, CTF3, impedance 384
 
  • A. Benot-Morell, L. Søby, M. Wendt
    CERN, Geneva, Switzerland
  • A. Benot-Morell, A. Faus-Golfe
    IFIC, Valencia, Spain
  • J.M. Nappa, S. Vilalte
    IN2P3-LAPP, Annecy-le-Vieux, France
  • S.R. Smith
    SLAC, Menlo Park, California, USA
  
  Funding: MINECO contract FPA2010-21456-C02-01, SEIC-2010-00028, U.S. Department of Energy contract DE-AC02-76SF00515
In collaboration with SLAC, LAPP and IFIC, a first prototype of a strip-line Beam Position Monitor (BPM) for the CLIC Drive Beam and its associated readout electronics has been successfully tested in the CLIC Test Facility linac (CTF3) at CERN. In addition, a modified prototype with downstream terminated strip-lines is under development to better suppress any unwanted RF signal interference. This paper presents the results of the beam tests, the most relevant design aspects for the modified strip-line BPM version and its expected performance. 		 
poster icon Poster TUPC12 [1.729 MB]  
 
TUPC13 System Overview and Design Considerations of the BPM System of the ESS Linac target, linac, ESS, beam-position 388
 
  • H. Hassanzadegan, A. Jansson, R. Zeng
    ESS, Lund, Sweden
  • A.J. Johansson
    Lund University, Lund, Sweden
  • K. Strniša
    Cosylab, Ljubljana, Slovenia
  • A. Young
    SLAC, Menlo Park, California, USA
  
  The ESS Linac will include in total more than 140 Beam Position Monitors of different sizes and types. The BPM system needs to measure the beam position, phase and intensity in all foreseen beam modes with a pulse rate of 14 Hz, duration of 2.86 ms and amplitude ranging form 5 mA to 62.5 mA. With respect to the BPM connection to the Machine Interlock System, the total response time must be less than 10 us. The signal level variations from one BPM to another along the Linac should be as small as possible to meet the requirements on the analog gain of the front-end electronics and the dynamic range of the digitizer card input. The other requirement is that the BPM system needs to give at least a rough estimation of the beam position and phase, even if the beam is significantly debouched, ex. during the Linac tuning phase. These requirements and their impact on the design of the BPM detector, the analog front-end electronics and the selection of the digitizer card are discussed in this paper along with a general description of the BPM system.  
poster icon Poster TUPC13 [3.050 MB]  
 
TUPC14 Development of a Low-Beta Button BPM for PXIE Project simulation, pick-up, beam-position, longitudinal 392
 
  • A. Lunin, N. Eddy, T.N. Khabiboulline, V.A. Lebedev, V.P. Yakovlev
    Fermilab, Batavia, USA
  
  The button BPM is under development for a low beta section of the Project X Injector Experiment (PXIE) at Fermilab. The presented paper includes an analytical estimation of the BPM performance as well a direct wakefield simulation with CST Particle Studio (on a hexahedral mesh). In addition we present a novel approach of a low beta beam interaction with BPM electrodes realized with ANSYS HFSS TD-solver on unstructured tetrahedral mesh. Both methods show a good agreement of BPM output signals for various beam parameters. Finally we describe the signal processing scheme and the electronics we are going to use.  
poster icon Poster TUPC14 [1.051 MB]  
 
TUPC15 BPM Electronics Upgrade for the Fermilab H− Linac Based Upon Custom Downconverter Electronics linac, controls, booster, beam-position 396
 
  • E.S.M. McCrory, N. Eddy, F.G.G. Garcia, S.U. Hansen, T. Kiper, M.Z. Sliczniak
    Fermilab, Batavia, USA
  
  As part of the Fermilab Proton Improvement Plan, the readout electronics for the Fermilab H− Linac has been upgraded. The new custom electronics provide a low cost solution to process the 2nd harmonic of the RF at 402.5MHz. A single 4 channel NIM-bin module is used to readout each 4 plate stripline BPM pickup with each module being locked to an external 805MHz machine reference from the low level RF. For each BPM a number of measurements are provided including average horizontal and vertical position, average intensity, and average relative phase for variable pulse lengths from a few μs up to 50~usec. The system is being exploited in a number of ways with new operations applications.  
poster icon Poster TUPC15 [1.731 MB]  
 
TUPC19 First Beam Tests of a Prototype Cavity Beam Position Monitor for the CLIC Main Beam single-bunch, beam-position, dipole, pick-up 411
 
  • F.J. Cullinan, S.T. Boogert, A. Lyapin, J.R. Towler
    JAI, Egham, Surrey, United Kingdom
  • W. Farabolini, T. Lefèvre, L. Søby, M. Wendt
    CERN, Geneva, Switzerland
  
  Beam position monitors (BPMs) throughout the CLIC (Compact Linear Collider) main linac and beam delivery system must routinely operate at 50 nm resolution and be able to make multiple position measurements within a single 156 ns long bunch train. A prototype cavity beam position monitor, designed to demonstrate this performance, has been tested on the probe beamline of CTF3 (the CLIC Test Facility). Sensitivity measurements of the dipole mode position cavity and of the monopole mode reference cavity have been made. The characteristics of signals from short and long bunch trains and the dominant systematic effects have also been studied.  
 
TUPC20 Technologies and R&D for a High Resolution Cavity BPM for the CLIC Main Beam CLIC, CTF3, pick-up, coupling 415
 
  • J.R. Towler, T. Lefèvre, L. Søby, M. Wendt
    CERN, Geneva, Switzerland
  • S.T. Boogert, F.J. Cullinan, A. Lyapin
    JAI, Egham, Surrey, United Kingdom
  
  The Main Beam (MB) LINAC of the Compact Linear Collider (CLIC) requires a beam orbit measurement system with a high spatial (50 nm) and high temporal (50 ns) resolution to resolve the beam position within the 156 ns long bunch train, traveling on an energy-chirped, minimum dispersive trajectory. A 15 GHz prototype cavity BPM has been commissioned in the probe beam-line of the CTF3 CLIC Test Facility. The performance and technical details of this prototype installation are discussed in this paper, including the 15 GHz analog down-converter, the data acquisition and the control electronics and software. An R&D outlook is given for the next steps, which requires a system of 3 cavity BPMs to investigate the full resolution potential.  
 
TUPC22 Cavity Beam Position Monitor in Multiple Bunch Operation for the ATF2 Interaction Point Region beam-position, feedback, collider, single-bunch 419
 
  • Y.I. Kim, D.R. Bett, N. Blaskovic Kraljevic, S.T. Boogert, P. Burrows, G.B. Christian, M.R. Davis, A. Lyapin, C. Perry
    JAI, Oxford, United Kingdom
  • J.C. Frisch, D.J. McCormick, J. Nelson, G.R. White
    SLAC, Menlo Park, California, USA
  • Y. Honda, T. Tauchi, N. Terunuma, J. Urakawa
    KEK, Ibaraki, Japan
  
  The Accelerator Test Facility 2 (ATF2) at KEK, Japan, is a scaled test beam line for the international linear collider (ILC) final focus system. There are two goals: firstly, to demonstrate focusing to 37 nm vertical beam size; secondly, to achieve a few nanometer level beam orbit stability at the focus point (the Interaction Point (IP)) in the vertical plane. High-resolution beam position monitors around the IP area (IPBPMs) have been developed in order to measure the electron beam position in that region with a resolution of a few nanometers in the vertical plane. Currently, the standard operation mode at ATF2 is single bunch, however, multiple bunch operation with a bunch spacing similar to the one foreseen for the ILC (around 300 ns) is also possible. IPBPMs have a low Q value resulting in a decay time of about 30 ns, and so should be able to measure the beam position of individual bunches without any significant performance degradation. The IPBPMs in the ATF2 extraction beam line have been tested in multibunch regime. This paper analyses the signals, processing methods and results for this mode.  
poster icon Poster TUPC22 [1.050 MB]  
 
TUPC24 The Design Strategy of Orbit Feedback System in the TPS feedback, controls, power-supply, storage-ring 423
 
  • C.H. Kuo, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, C.Y. Wu
    NSRRC, Hsinchu, Taiwan
  
  TPS (Taiwan Photon Source) is a 3 GeV synchrotron light source which is being constructed at NSRRC. The BPM electronic is based on uTCA platform, is used for various request and function reasons. The orbit feedback system design is based on open structure, modularization and highly integration. There are many advantages that orbit feedback system is embedded in the BPM crate with FPGA modules. High throughput backplane, data transfer and processing support rich function for waveform record, diagnostic, beam study and transient analysis. The design and implementation result of the system will be reported in this conference.  
 
TUPC25 Design of the SwissFEL BPM System pick-up, XFEL, undulator, linac 427
 
  • B. Keil, R. Baldinger, R. Ditter, W. Koprek, R. Kramert, F. Marcellini, G. Marinkovic, M. Roggli, M. Rohrer, M. Stadler, D.M. Treyer
    PSI, Villigen PSI, Switzerland
  
  SwissFEL is a Free Electron Laser (FEL) facility being constructed at PSI, based on a 5.8GeV normally conducting main linac. A photocathode gun will generate two bunches with 28ns spacing at 100Hz repetition rate, with a nominal charge range of 10-200pC. A fast beam distribution kicker will allow to distribute one bunch to a soft X-ray undulator line and the other bunch to a 0.1nm hard X-ray undulator line. The SwissFEL electron beam position monitor (BPM) system will employ three different types of dual-resonator cavity BPMs, since the accelerator has three different beam pipe apertures. In the injector and main linac (38mm and 16mm aperture), 3.3GHz cavity BPMs will be used, where a low Q of ~40 was chosen to minimize crosstalk of the two bunches*. In the undulators that just have single bunches and 8mm BPM aperture, a higher Q will be chosen. This paper reports on the development status of the SwissFEL BPM system. Synergies as well as differences to the E-XFEL BPM system** will also be highlighted.
* F. Marcellini et al., "Design of Cavity BPM Pickups For SwissFEL", Proc. IBIC'12, Tsukuba, Japan, 2012.
** B. Keil et al., "The European XFEL BPM System", Proc. IPAC'10, Kyoto, Japan, 2010. 		 
poster icon Poster TUPC25 [1.074 MB]  
 
TUPC26 Beam-line Diagnostics at the Front End Test Stand (FETS), Rutherford Appleton Laboratory, Oxfordshire, UK linac, rfq, emittance, ion-source 431
 
  • G.E. Boorman, S.M. Gibson
    Royal Holloway, University of London, Surrey, United Kingdom
  • G.E. Boorman, S.M. Gibson
    JAI, Egham, Surrey, United Kingdom
  • R.T.P. D'Arcy, S. Jolly
    UCL, London, United Kingdom
  • C. Gabor
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  • S.R. Lawrie, A.P. Letchford
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  
  The H− ion source and beam-line at FETS will require the beam current and beam position to be continually monitored. Current transformer toroids will measure the beam current and beam position monitors (BPM) will determine the beam position. The ion source delivers pulses at a rate of 50Hz with a current up to 60mA, each pulse is 2ms long, and a 324MHz micro-bunch structure imposed by the radio frequency quadrapole (RFQ) accelerating structure. The toroid outputs will be acquired on a fast oscilloscope. The BPM design is still under consideration (shorted strip-line or button type) but the processing for both types is similar and has been designed, with simulated measurements made. Each BPM uses four pickups, at a frequency of 324MHz, which are mixed using RF electronics to an intermediate frequency of 10.125MHz. The resulting signals are then digitized at 40.500MHz and processed in an FPGA to produce the position and phase of the beam at each BPM location, with a precision of better than 100μm and 0.05rad. The measurements from the toroids and BPMs will be via EPICS servers at every pulse.  
poster icon Poster TUPC26 [0.660 MB]  
 
TUPF36 Analysis of Modulation Signals Generated in the TE Wave Detection Method For Electron Cloud Measurements electron, resonance, vacuum, 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. 		 
 
WEBL2 Applications of Stripline and Cavity Beam Position Monitors in Low-Latency, High-Precision, Intra-Train Feedback Systems feedback, kicker, beam-position, extraction 630
 
  • M.R. Davis, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, G.B. Christian, Y.I. Kim, C. Perry
    JAI, Oxford, United Kingdom
  
  Two, low-latency, sub-micron beam position monitoring (BPM) systems have been developed and tested with beam at the KEK Accelerator Test Facility (ATF2). One system (‘upstream’), based on stripline BPMs uses fast analogue front-end signal processing and has demonstrated a position resolution as low as 400nm for beam intensities of ~1 nC, with single-pass beam. The other (‘IP’) system, based on low-Q cavity BPMs and utilising custom signal processing electronics designed for low latency, provides a single pass resolution of approximately 100nm. The BPM position data are digitised by fast ADCs on a custom FPGA-based feedback controller and used in three modes: 1) the upstream BPM data are used to drive a pair of local kickers nominally orthogonal in phase in closed-loop feedback mode; 2) the upstream BPM data are used to drive a downstream kicker in the ATF2 final focus region in feedforward mode; 3) the IP cavity BPM data are used to drive a local downstream kicker in the ATF2 final focus region in closed-loop feedback mode. In each case the beam jitter is measured downstream of the final focus system with the IP cavity BPMs. The relative performance of these systems is compared.  
slides icon Slides WEBL2 [1.934 MB]  
 
WEPC06 Beam Instrumentation in the ESS Cold Linac linac, ESS, cryogenics, instrumentation 667
 
  • C. Böhme, B. Cheymol, I. Dolenc Kittelmann, H. Hassanzadegan, A. Jansson
    ESS, Lund, Sweden
  
  Parts of the linac of the European Spallation Source will consist of cryogenic cavity modules. In between these will be warm sections at room temperature to host amongst others the beam instrumentation. Each of the warm sections will host two beam position monitors and one or two other instruments, which might be a beam current monitor, invasive and non-invasive transverse beam profile monitor, bunch shape monitor, or halo monitor. The concept of the warm section layout will be shown and the planned instrumentation will be presented.  
 
WEPC07 Development of the RF Front End Electronics for the SIRIUS BPM System controls, coupling, emittance, electron 670
 
  • R.A. Baron, F.H. Cardoso, S.R. Marques, J.L.B. Neto
    LNLS, Campinas, Brazil
  • J.-C. Denard
    SOLEIL, Gif-sur-Yvette, France
  
  Tight stability requirements for new low emittance light sources, such as SIRIUS being built in Brazil, strongly depend on the BPM RF Front-End performance. Small nonlinearities, uneven temperature drifts and excess noise can spoil the performance of the whole digital BPM system and orbit correction. Calibration and temperature control schemes have been tested in order to suppress position measurement drifts during user beam delivery down to a fraction of micrometer. A method for measuring electronic component nonlinearities at mdB scale is also presented.  
poster icon Poster WEPC07 [1.236 MB]  
 
WEPC08 Vibration Measurement and its Effect on Beam Stability at NSLS2 storage-ring, ground-motion, damping, feedback 674
 
  • W.X. Cheng, A.K. Jain, S. Krinsky, S.K. Sharma, C.J. Spataro
    BNL, Upton, Long Island, New York, USA
  
  Vibration measurements have been carried out at NSLS2. The floor has more than 100nm RMS vertical motion during workdays (>1Hz). This motion reduces to 30nm RMS during night and weekends. Traffic on the nearby expressway is considered to be the major source of ground motion. Weather (wind) and utility system induced vibrations are other possible factors on floor motion. Vibrations have been measured at various locations, like the tunnel and experiment floor, HXN long beamline satellite building floor, high stability BPMs, Quadrupole magnets etc. Assume a typical un-correlated motion of Quadrpole magnets of 100nm, beam orbit jitter is around 4-7 microns. Fast orbit feedback will control the orbit stability within 10% of beam size.  
 
WEPC09 Performance of NSLS2 Button BPM simulation, storage-ring, booster, vacuum 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.  
 
WEPC11 Radiation Resistance Testing of Commercial Components for the New SPS Beam Position Measurement System radiation, SPS, CERN, beam-position 686
 
  • C. Deplano, J. Albertone, T.B. Bogey, J.L. Gonzalez, J.-J. Savioz
    CERN, Geneva, Switzerland
  
  A new Front-End (FE) electronics is under development for the SPS Multi Orbit POsition System (MOPOS). To cover the large dynamic range of beam intensities (70dB) to be measured in the SPS, the beam position monitor signals are processed using logarithmic amplifiers. They are then digitized locally and transmitted via optical fibers over long distances (up to 1km) to VME acquisition boards located in surface buildings. The FE board is designed to be located in the SPS tunnel, where it must cope with a radiation dose rate of up to 100 Gy per year. Analogue components, such as Logarithmic Amplifiers, ADC-Drivers and Voltage regulators, have been tested at PSI for radiation hardness, while several families of bidirectional SFP, both single-fiber and double-fiber, have been tested at both PSI and CNRAD. This paper gives a description of the overall system architecture and presents the results of the radiation hardness tests in detail.  
poster icon Poster WEPC11 [3.299 MB]  
 
WEPC13 Optimisation of the SVD Treatment in the Fast Orbit Correction of the ESRF Storage Ring ESRF, feedback, storage-ring, injection 694
 
  • E. Plouviez, F. Epaud, L. Farvacque, J.M. Koch
    ESRF, Grenoble, France
  
  The ESRF fast orbit correction system has been in operation since May 2012. The orbit correction scheme relies classically on the calculation of a correction orbit based on the SVD analysis of the response matrix of our 224 BPMs to each of our 96 correctors. The rate of the calculation of the corrections is 10 KHz; we use a PI loop achieving a bandwidth of 150Hz completed with a narrow band pass filter with extra gain at 50Hz. In order to make the best use of the correctors dynamic range and of the resolution of the calculation, it can be useful to limit the bandwidth of loop for the highest order vectors of the SVD, or even to totally remove some of these vectors from the correction down to DC. Removing some of the eigen vectors while avoiding that the loop becomes unstable usually increases a lot the complexity of the matrix calculations: we have developed an algorithm which overcomes this problem; The test of this algorithm is presented. We present also the beneficial effect at high frequency of the limitation of the gain of the correction of the highest SVD eigen vectors on the demand of the peak strength of the correctors and on the resolution of the correction calculation.  
poster icon Poster WEPC13 [0.974 MB]  
 
WEPC14 Development of High Precision Beam Position Monitor Readout System with Narrow Bandpass Filters for the KEKB Injector Linac Towards the SuperKEKB positron, beam-position, linac, KEKB 698
 
  • R. Ichimiya, K. Furukawa, F. Miyahara, M. Satoh, T. Suwada
    KEK, Ibaraki, Japan
  
  The SuperKEKB accelerator complexes are now being upgraded to bring the world highest luminosity (L=8x1035/cm2/s). Hence, the KEKB Injector Linac is required to produce: electron: 20 mm mrad (7GeV, 5nC), positron: 10 mm mrad (4GeV, 4nC). To achieve this, the accelerator components have to be aligned within ± 0.1mm (1 σ). BPM is essential instrumentation for Beam Based Alignment, and is required one magnitude better position resolution to get better alignment results. Since current BPM readout system using oscilloscopes has ~50um position resolution, we decided to develop high precision BPM readout system with narrow bandpass filters. It handles two bunches with 96ns interval and has a dynamic range between 0.1nC (for photon factory) to 10nC (positron primary). To achieve these criteria, we adopt semiconductor attenuators and optimized two-stage Bessel filters at 300MHz center frequency to meet both time and frequency domain constraints. To correct position drift due to gain imbalance during operation, calibration pulses are output to the BPM between beam cycles (20ms). The beam position and charge calculations are performed by onboard FPGA to achieve fast readout cycle.  
poster icon Poster WEPC14 [3.039 MB]  
 
WEPC15 Development of the Beam Position Monitors System for the LINAC of SPIRAL2 linac, SPIRAL2, ion, transverse 702
 
  • P. Ausset, M. Ben Abdillah, J. Lesrel, E. Marius
    IPN, Orsay, France
  • T. Ananthkrishnan, S.K. Bharade, G. Joshi, P.D. Motiwala, C.K. Pithawa
    BARC, Trombay, Mumbai, India
  • V. Nanal, R.G. Pillay
    TIFR, Mumbai, India
  
  The SPIRAL 2 facility will deliver stable heavy ion and deuteron beams at very high intensity, producing and accelerating light and heavy rare ion beams. The driver will accelerate between 0.15mA and 5 mA deuteron beam up to 20 MeV/u and q/A=1/3 heavy ions up to 14.5 MeV/u. It is being built on the site of the Grand Accelerator National d’Ions Lourds at CAEN (France) The accurate tuning of the LINAC is essential for the operation of SPIRAL2 and requires from the Beam Position Monitor (BPM) system the measurements of the beam transverse position, the phase of the beam with respect to the radiofrequency voltage and the beam energy. This paper addresses the advancement made during the last twelve months on the realization of the 22 BPM required for the SPIRAL 2 LINAC. The BPM sensors are now completed and tested. The design of the acquisition card for the BPM is given and will be described. The prototype card is now under test and the first results are given. The aim is to verify the main parameters: sensitivity, position and phase measurement and the appropriate behavior of the BPM acquisition card in all cases (pulsed, electrode signal reconstruction, interlock, post mortem)  
 
WEPC16 The Design of BPM Electronic System for CSNS RCS pick-up, extraction, injection, beam-position 706
 
  • W. Lu, H.Y. Sheng, X.C. Tian, J.W. Zhao, Y.B. Zhao
    IHEP, Bejing, People's Republic of China
  
  A Beam Position Monitor (BPM) system has been designed for the Rapid Cycling Synchrotron (RCS) at the China Spallation Neutron Source (CSNS) to acquire beam position information. This article introduces the design and implementation of the BPM electronic system. The challenge of designing the BPM electronics is to acquire and process the signal with large dynamic range (5.8mV~32V) and changing width (80ns to 500ns). The analog circuit described in this paper, which is constructed of a single-stage operational amplifier and an analog switch, can cover the input signal with large dynamic range. Because of the minimum bunch length (80ns) and the requirement of position resolution, a 14 bit 250MHz ADC is adopted to digitize the signal. Besides, for BPM system, the demand of an accurate real-time position monitoring is mandatory. The algorithm developed in an FPGA is able to make Bunch-by-Bunch position calculation and Closed Orbit position calculation in real time. Also, some preliminary test results will be presented and discussed, which show that the resolution of Bunch-by-Bunch position is 0.8mm when the input signal is 5.8mV and the resolution of Closed Orbit position is 50um.  
poster icon Poster WEPC16 [0.937 MB]  
 
WEPC17 Design and Simulation of Beam Position Monitor for the CADS Injector I Proton Linac simulation, pick-up, linac, impedance 710
 
  • Y.F. Sui, J.S. Cao, H.Z. Ma, Q. Ye, J. Yue
    IHEP, People's Republic of China
  
  Funding: Work supported by the National Natural Science Foundation of China (NO. 11205172)
Beam Position Monitors (BPM) based on both capacitive and stripline pick-ups are designed for the China Accelerator Driven Subcritical system (C-ADS) Injector I proton LINAC. The BPM will be installed to measure the transverse beam position in the LINAC, of which the beam parameters are listed as current 10mA, energy 10MeV and the repetition frequency 325MHz. This contribution presents the status of the BPM design development and focuses on the design of the pick-ups and CST Particle Studio simulation results, including impedance, sensitivity, time domain, frequency domain response, etc. The main goal of the simulation is optimization of the mechanical design. 		 
 
WEPC18 Development of Compact Electronics Dedicated to Beam Position Monitors in Injectors and Boosters booster, ESRF, beam-position, controls 713
 
  • G. Jug, M. Cargnelutti
    I-Tech, Solkan, Slovenia
  • K.B. Scheidt
    ESRF, Grenoble, France
  
  The need for state-of-the-art electronics for data-acquisition and processing of BPM signals in Injector and/or Booster Synchrotrons is being addressed in a development that aims at making such system available with less complexity and yet fulfilling precisely the needs of such specific BPMs. The ESRF Booster Synchrotron uses 75 BPMs in its 300m circumference to measure the orbit along its acceleration cycle of 50 milliseconds for the electron beam from 0.2 to 6GeV. The 25 year old electronics of these BPMs are in need of replacement. While BPM developments in recent years have focused on devices for Storage Rings that face extreme requirements like sub-micron drift with time, beam intensity, etc. that result in complicated implementation schemes. This new development combines both the simplification in the measurement concept and the implementation of novelties like compact design integrating RF electronics, with power-over-Ethernet supply and passive cooling, a powerful System-on-Chip engine and easy communication via SCPI commands. This paper will present the full design concept and its aimed functionalities as a BPM device that should offer an excellent price/performance ratio.  
 
WEPC19 Performance of Injection Beam Position Monitors in the J-PARC RCS injection, linac, monitoring, bunching 716
 
  • N. Hayashi, P.K. Saha
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  
  It is important to monitor the injected beam trajectory and position into a synchrotron ring. In the J-PARC RCS, there are two specialized beam position monitors (BPM) in the first arc section in order to perform continuous monitoring. They detect the linac RF frequency 324 MHz or its second harmonics, these contributions quickly decrease after a few turns in the ring. Therefore, they are sensitive only just injected beam. The RCS adopts the multi-turn injection and transverse painting. These monitors are useful to check the beam behavior on-line.  
 
WEPC21 Design and Beam Test Results of Button BPMs for the European XFEL pick-up, XFEL, controls, DESY 723
 
  • D.M. Treyer, R. Baldinger, R. Ditter, B. Keil, W. Koprek, G. Marinkovic, M. Roggli
    PSI, Villigen PSI, Switzerland
  • D. Lipka, D. Nölle, S. Vilcins
    DESY, Hamburg, Germany
  
  Funding: Swiss State Secretariat for Education, Research and Innovation
The European X-ray Free Electron Laser (E-XFEL) will use a total ~300 button BPMs along the whole accelerator, as well as 160 cavity BPMs. The pickups for the button BPMs have been designed by DESY, whereas the electronics has been developed by PSI. This paper gives an overview of the button BPM system, with focus on the RF front end electronics, signal processing, and overall system performance. Measurement results achieved with prototypes installed at FLASH/DESY and at the SwissFEL Injector Test Facility (SITF) are presented. The position noise obtained with button pickups in a 40.5 mm aperture beam pipe is as low as ~11 um at 20 pC bunch charge. 		 
poster icon Poster WEPC21 [1.595 MB]  
 
WEPC23 Design of an Ultra-Compact Stripline BPM Receiver using MicroTCA for LCLS-II at SLAC SLAC, LCLS, linac, beam-position 731
 
  • C. Xu, S. Babel, S. L. Hoobler, R.S. Larsen, J.J. Olsen, S.R. Smith, T. Straumann, D. Van Winkle, A. Young
    SLAC, Menlo Park, California, USA
  
  Funding: Work supported by U.S. Department of Energy under Contract Numbers DE-AC02-06CH11357 and DE-AC02-76SF00515
The Linac Coherent Light Source II (LCLS II) is a free electron laser (FEL) light source. LCLS II will be able to produce 0.5 to 77 Angstroms soft and hard x-rays. In order to achieve this high level of performance, the electron beam needs to be stable and accurate. The LCLS II stripline BPM system has a dynamic range of 10pC to 1nC beam charge. The system has a 3.5 micrometer resolution at 250pC beam charge in an one inch diameter stripline BPM structure. The BPM system uses the MicroTCA physics platform that consists of analog front-end (AFE) and 16-bit analog to digital convertor (ADC) module. The paper will discuss the hardware design, architecture, and performance measurements on the SLAC LINAC. The hardware architecture includes bandpass filter at 300MHz with 15 MHz band-width, and BPM calibration process without communicating with the CPU module. The system will be able to process multibunch beams with 40ns spacing. 		 
poster icon Poster WEPC23 [1.769 MB]  
 
WEPC24 Performance Measurements of the New X-Band Cavity BPM Receiver LCLS, undulator, dipole, SLAC 735
 
  • A. Young, J.E. Dusatko, S. L. Hoobler, J.J. Olsen, T. Straumann
    SLAC, Menlo Park, California, USA
  • C. Kim
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  Funding: Work supported by U.S. Department of Energy under Contract Numbers DE-AC02-06CH11357 and DE-AC02-76SF00515
SLAC is developing a new X-band Cavity BPM receiver for use in the LCLS-II. The Linac Coherent Light Source II (LCLS-II) will be a free electron laser (FEL) at SLAC producing coherent 0.5-77 Angstroms hard and soft x-rays. To achieve this level of performance precise, stable alignment of the electron beam in the undulator is required. The LCLS-II cavity BPM system will provide single shot resolution better than 50 nm resolution at 200 pC*. The Cavity BPM heterodyne receiver is located in the tunnel close to the cavity BPM. The receiver will processes the TM010 monopole reference cavity signal and a TM110 dipole cavity signal at approximately 11 GHz using a heterodyne technique. The heterodyne receiver will be capable of detecting a multibunch beam with a 50ns fill pattern. A new LAN communication daughter board will allow the receiver to talk to an input-output-controller (IOC) over 100 meters to set gains, control the phase locked local oscillator, and monitor the status of the receiver. We will describe the design methodology including noise analysis, Intermodulation Products analysis.
* Commissioning and Performance of LCLS Cavity BPMs, Stephen Smith, et al., Proc. of PAC 2009 		 
poster icon Poster WEPC24 [0.251 MB]  
 
WEPC25 Optimisation of a Split Plate Position Monitor for the ISIS Proton Synchrotron beam-position, coupling, simulation, proton 739
 
  • C.C. Wilcox, J.C. Medland, S.J. Payne, A. Pertica, M.A. Probert
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  
  A new Beam Position Monitor (BPM) has been designed for the ISIS proton accelerator facility at the Rutherford Appleton Laboratory in the UK. The new monitor, which will be installed in the beam line to Target 1, is of a ‘split plate’ design which utilises two pairs of electrodes to allow the beam position to be measured simultaneously in the horizontal and vertical planes. Simulations carried out using the CST low frequency solver have highlighted the inaccuracies in the measured beam position caused by strong inter-electrode coupling in such a monitor. This coupling, along with imbalanced electrode capacitances, leads to reduced sensitivity to changes in beam position as well as producing a positional offset error. This paper describes how the problems associated with inter-electrode coupling have been removed with the addition of grounded rings placed between each of the four electrodes. The design and positioning of the rings also ensured that the four electrode capacitances were matched. The results are presented both as CST simulations of ‘thin wire’ beam position measurements and results from bench measurements of a prototype dual plane BPM.  
 
WEPC33 Upgrade of Beam Phase Monitors for the ESRF Injector and Storage Ring storage-ring, booster, injection, ESRF 757
 
  • K.B. Scheidt, B. Joly
    ESRF, Grenoble, France
  
  The measurement of the phase relation between the stored beam in the Storage Ring and the beam circulating in the Booster Synchrotron is now done with high precision and at high speed using a single unit of commercial BPM electronics. The quadrature demodulation, driven by a common PLL, done in these digital electronics on each of its four RF input channels makes the relative measurement of the I/Q components, hence phase relation, easy and strait forward. The RF signals of the relatively low current Booster come from two stripline outputs while that of the Storage Ring from two small BPM buttons. Treating simultaneously four signals, thus with a redundancy of two to measure the phase between two sources, allows to perform intrinsic shot-to-shot cross verifications on resolution and reproducibility. The long-term stability of this device has also been successfully assessed by independent verifications against time and temperature drifts. An identical unit has now been added for phase measurements between the Storage Ring beam and the RF cavity signals. Results with beam and assessment of its scope of performance will be presented on both systems.  
poster icon Poster WEPC33 [0.836 MB]  
 
THAL3 Charge Distribution Measurements at ALBA photon, synchrotron, electron, injection 925
 
  • L. Torino, U. Iriso
    CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
  
  Two different set-ups are used to perform quantitative measurements of the charge distribution at ALBA. The first consists in a real-time analysis of data coming from the Fast Current Transformer or from the buttons of a Beam Position Monitor installed in the Storage Ring. The second is performed at the diagnostic visible beamline Xanadu, using a Photomultiplier that measures the temporal distribution of synchrotron light. In both cases a quantitative estimation of the charge distribution is obtained after a dedicated data treatment and beam current measurements from the DCCT. We compare results with both methods, and discuss differences and limitations with respect to bunch purity measurements with the Time Correlated Single Photon Counting technique.  
slides icon Slides THAL3 [15.369 MB]