BPMs and Beam Stability
Paper Title Page
MOPG01 Design, Production and Tests of Button Type BPM for TAC-TARLA IR FEL Facility 27
  • M.T. Gundogan, Ö. Yavaş
    Ankara University, Faculty of Engineering, Tandogan, Ankara, Turkey
  • A.A. Aydin, E. Kasap
    Gazi University, Faculty of Arts and Sciences, Teknikokullar, Ankara, Turkey
  • Ç. Kaya
    Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
  Funding: Ankara University
Turkish Accelerator and Radiation Laboratory in Ankara (TARLA) facility is proposed as an IR FEL and Bremsstrahlung facility as the first facility of Turkish Accelerator Center (TAC) in Golbasi Campus of Ankara University. TARLA is proposed to generate oscillator mode FEL in 3-250 microns wavelengths range and Bremsstrahlung radiation. It will consist of normal conducting injector system with 250 keV beam energy and two superconducting RF accelerating modules in order to accelerate the beam 15-40 MeV. The electron beam will be in both continuous wave (CW) and macro pulse (MP) modes. The bunch charge will be limited by 77pC and the average beam current will be 1 mA. To detect electron beam position inside beam line, BPM (Beam Position Monitor) has to use through beam line. Wall current monitor based systems button type TARLA BPM are briefly mentioned. In this study, simulation results of the calculations in CST, production and test studies for button type TARLA BPMs are presented. Mechanical and electronic designs, antenna simulations, and the latest testing procedures are determined for button type BPMs.
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG01  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
MOPG03 Investigation of Transverse Beam Instability Induced by an In-vacuum Undulator at SPEAR3 31
  • K. Tian, J.J. Sebek, J.L. Vargas
    SLAC, Menlo Park, California, USA
  Funding: Work supported by U.S. Department of Energy Contract No. DE-AC02-76SF00515
Vertical beam instabilities have been observed at SPEAR3 when a newly installed in-vacuum undulator (IVUN) is operated at a set of narrow gap settings. The source of the instabilities is believed to be vertically deflecting trapped modes inside the IVUN tank that are excited by the beam. We have used beam-based measurements to characterize the frequencies and strengths of the excited modes using both our bunch-by-bunch feedback system and a spectrum analyzer. Using numerical simulations of our IVUN structure, we have found modes with high shunt impedance near the measured frequencies. Recently, we have successfully measured these IVUN modes during our current downtime. In this paper, we will report on the measurements, simulations, and plans to damp these modes.
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG03  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
MOPG05 Transient Studies of the Stripline Kicker for Beam Extraction from CLIC Damping Rings 35
  • C. Belver-Aguilar, M.J. Barnes
    CERN, Geneva, Switzerland
  Stripline kickers are generally assumed to have equal contributions from the electric and magnetic field to the total deflection angle, for ultra-relativistic beams. Hence parameters of the striplines, such as the characteristic impedance, the field homogeneity and the deflection angle are typically determined by simulating the striplines from an electrostatic perspective. However recent studies show that, when exciting the striplines with a trapezoidal current pulse, the magnetic field changes during the flat-top of the pulse, and this can have a significant effect upon the striplines performances. The transient solver of Opera2D has been used to study the magnetic field, for the striplines to be used for beam extraction from the CLIC damping rings, when exciting the electrodes with a pulse of 1 us flat-top and 100 ns rise and fall times. The time dependence of the characteristic impedance, field homogeneity and deflection angle are presented in this paper. In addition, two solutions are proposed to improve the flatness of the magnitude of the magnetic field throughout the flat-top of the pulse, and the predicted results are reported.  
poster icon Poster MOPG05 [1.557 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG05  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
MOPG06 First Beam Tests of the APS MBA Upgrade Orbit Feedback Controller 39
  • N. Sereno, N.D. Arnold, A.R. Brill, H. Bui, J. Carwardine, G. Decker, B. Deriy, L. Emery, R.I. Farnsworth, T. Fors, R.T. Keane, F. Lenkszus, R.M. Lill, D.R. Paskvan, A.F. Pietryla, H. Shang, S.E. Shoaf, S. Veseli, J. Wang, S. Xu, B.X. Yang
    ANL, Argonne, Illinois, USA
  Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357
The new orbit feedback system required for the APS multi-bend acromat (MBA) ring must meet challenging beam stability requirements. The AC stability requirement is to correct rms beam motion to 10 \% the rms beam size at the insertion device source points from 0.01 to 1000 Hz. The vertical plane represents the biggest challenge for AC stability which is required to be 400 nm rms for a 4 micron vertical beam size. In addition long term drift over a period of 7 days is required to be 1 micron or less at insertion device BPMs and 2 microns for arc bpms. We present test results of the MBA prototype orbit feedback controller (FBC) in the APS storage ring. In this test, four insertion device BPMs were configured to send data to the FBC for processing into four fast corrector setpoints. The configuration of four bpms and four fast correctors creates a 4-bump and the configuration of fast correctors is similar to what will be implemented in the MBA ring. We report on performance benefits of increasing the sampling rate by a factor of 15 to 22.6 kHz over the existing APS orbit feedback system, limitations due to existing storage ring hardware and MBA orbit feedback design.
poster icon Poster MOPG06 [6.490 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG06  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
MOPG07 First Operational Experience with the LHC Diode ORbit and OScillation (DOROS) System 43
  • M. Gąsior, G. Baud, J. Olexa, G. Valentino
    CERN, Geneva, Switzerland
  The LHC started high-energy operation in 2015 with new tertiary collimators, equipped with beam position monitors embedded in their jaws. The required resolution and stability of the beam orbit measurements linked to these BPMs were addressed by the development of a new Diode ORbit and OScillation (DOROS) system. DOROS converts the short BPM electrode pulses into slowly varying signals by compensated diode detectors, whose output signals can be precisely processed and acquired with 24-bit ADCs. This scheme allows a sub-micrometre orbit resolution to be achieved with robust and relatively simple hardware. The DOROS system is also equipped with dedicated channels optimised for processing beam oscillation signals. Data from these channels can be used to perform betatron coupling and beta-beating measurements. The achieved performance of the DOROS system triggered its installation on the beam position monitors located next to the LHC experiments for testing the system as an option of improving the beam orbit measurement in the most important LHC locations. After introducing the DOROS system, its performance is discussed through both, beam and laboratory measurements.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG07  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
MOPG08 Beam Position Monitors for LEReC 47
  • Z. Sorrell, P. Cerniglia, R.L. Hulsart, K. Mernick, R.J. Michnoff
    BNL, Upton, Long Island, New York, USA
  Funding: Work supported by Brookhaven Science Associates, LL C under Contract No. DE-AC02-98CH10886 with the U.S. Dept. of Energy
The operating parameters for Brookhaven National Laboratory's Low Energy RHIC Electron Cooling (LEReC) project create a unique challenge. To ensure proper beam trajectories for cooling, the relative position between the electron and the ion beam needs to be known to within 50μm. In addition, time of flight needs to be provided for electron beam energy measurement. Various issues have become apparent as testing has progressed, such as mismatches in cable impedance and drifts due to temperature sensitivity. This paper will explore the difficulties related to achieving the level of accuracy required for this system, as well as the potential solutions for these problems.
poster icon Poster MOPG08 [3.304 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG08  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
MOPG09 The Orbit Correction Scheme of the New EBS of the ESRF 51
  • E. Plouviez, F. Uberto
    ESRF, Grenoble, France
  The ESRF storage ring is going to be upgraded into an Extremely Bright Source(EBS). The orbit correction system of the EBS ring will require 320 BPMs and 288 correctors instead of 224 BPMs and 96 correctors for the present ring. On the new ring, we are planning to reuse 192 Libera Brilliance electronics and 96 fast correctors power supplies and the 8 FPGA controllers of the present system and to add 128 new BPMs electronics and 196 new correctors power supplies. These new BPM electronics and power supplies will not have the fast 10 KHz data broadcast capability of the components of the present system. So we plan to implement an hybrid slow/ fast correction scheme on the SR of the EBS in order to reuse the present fast orbit correction system on a reduced set of the BPMs and correctors and combine this fast orbit correction with an orbit correction performed at a slower rate using the full set of BPMs and correctors. We have made simulations to predict the efficiency of this scheme for the EBS and tested on the present ring a similar orbit correction scheme using only 160 BPMs and 64 correctors for the fast corrections . We present the results of our simulations and experiments.  
poster icon Poster MOPG09 [4.054 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG09  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
MOPG10 BPM Stabiltiy Studies for the APS MBA Upgrade 55
  • R.M. Lill, N. Sereno, B.X. Yang
    ANL, Argonne, Illinois, USA
  Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source (APS) is currently in the preliminary design phase for the multi -bend achromat (MBA) lattice upgrade. Beam stability is critical for the MBA and will require long term drift defined as beam motion over a seven-day timescale to be no more than 1 micron at the insertion device locations and beam angle change no more than 0.5 micro-radian. Mechanical stability of beam position monitor (BPM) pickup electrodes mounted on insertion device vacuum chambers place a fundamental limitation on long-term beam stability for insertion device beamlines. We present the design and implementation of using prototype mechanical motion system (MMS) instrumentation for quantifying this type of motion specifically in the APS accelerator tunnel and experiment hall floor under normal operating conditions. The MMS presently provides critical position information on the vacuum chamber and BPM support systems. Initial results of the R&D prototype systems have demonstrated that the chamber movements far exceed the long-term drift tolerance specified for the APS Upgrade MBA storage ring.
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG10  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
MOPG11 Beam Commissioning of TPS Fast Orbit Feedback System 59
  • P.C. Chiu, Y.-S. Cheng, K.T. Hsu, K.H. Hu, C.H. Huang
    NSRRC, Hsinchu, Taiwan
  Submicron orbit stability for a low emittance synchrotron light source are essential. Besides locating and removing the existing perturbations, active orbit feedback is applied to improve the orbit stability below sub-micron range from DC to a few hundreds of Hertz. Efforts to investigate orbit stability and stabilization at TPS will be addressed in this report.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG11  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
MOPG12 A Wire-Based Methodology to Analyse the Nanometric Resolution of an RF Cavity BPM 63
  • S. Zorzetti, K. Artoos, F.N. Morel, P. Novotny, D. Tshilumba, M. Wendt
    CERN, Geneva, Switzerland
  • L. Fanucci
    Università di Pisa, Pisa, Italy
  Funding: The PACMAN project is funded by the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 606839
Resonant Cavity Beam Position Monitors (RF-BPMs) are diagnostic instruments capable of achieving beam position resolutions down to the nanometre scale. To date, their nanometric resolution capabilities have been predicted by simulation and verified through beam-based measurements with particle beams. In the frame of the PACMAN project at CERN, an innovative methodology has been developed to directly observe signal variations corresponding to nanometric displacements of the BPM cavity with respect to a conductive stretched wire. The cavity BPM of this R&D study operates at the TM110 dipole mode frequency of 15GHz. The concepts and details of the RF stretched wire BPM test-bench to achieve the best resolution results are presented, along with the required control hardware and software.
poster icon Poster MOPG12 [1.692 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG12  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
MOPG13 MicroTCA.4 Based Optical Frontend Readout Electronics and its Applications 67
  • K.P. Przygoda, Ł. Butkowski, M.K. Czwalinna, H. Dinter, C. Gerth, E. Janas, F. Ludwig, S. Pfeiffer, H. Schlarb, Ch. Schmidt, M. Viti
    DESY, Hamburg, Germany
  • R. Rybaniec
    Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
  In the paper the MicroTCA.4 based optical frontend readout (OFR) electronics and its applications for beam arrival time monitor (BAM) and fast beam based feed-back (BBF) is presented. The idea is to have a possibility to monitor the modulation density of the optical laser pulses by the electron bunches and apply this information for the BBF. The OFR composed of double width fast mezzanine card (FMC) and advanced mezzanine card (AMC) based FMC carrier. The FMC module consists of three optical channel inputs (data and clock), two optical channel outputs (beam arrival time), 250 MSPS ADCs, clock generator module (CGM) with integrated 2.8 GHz voltage control oscillator (VCO). The optical signals are detected with 800 MHz InGaAs photodiodes, conditioned using 2 GHz current-feedback amplifiers, filtered by 3.3 GHz differential amplifiers and next direct sampled with 16-bit 900 MHz of analog bandwidth ADCs. The CGM is used to provide clock outputs for the ADCs and for the FMC carrier with additive output jitter of less than 300 fs rms. The BAM application has been implemented using Virtex 5 FPGA and measured with its performance at Free Electron LASer in Hamburg (FLASH) facility.  
poster icon Poster MOPG13 [3.991 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG13  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
MOPG14 The Use of Single-crystal CVD Diamond as a Position Sensitive X-ray Detector 71
  • E. Griesmayer, P. Kavrigin, Ch. Weiss
    CIVIDEC Instrumentation, Wien, Austria
  • C. Bloomer
    DLS, Oxfordshire, United Kingdom
  Synchrotron light sources generate intense beams of X-ray light for beamline experiments, and the stability of these X-ray beams has a large impact on the quality of the experiments that can be performed. User experiments increasingly utilise micro-focus techniques, focusing the X-ray beam size to below 10 microns at the sample point, with beamline detectors operating at kHz bandwidths. Thus, there is a demand for non-invasive diagnostic techniques that can reliably monitor the X-ray beam position with sub-micron accuracy in order to characterise X-ray beam motion, at corresponding kHz bandwidths. Reported in this paper are measurements from single-crystal CVD diamond detectors, and a comparison with the previous-generation of polycrystalline CVD diamond detectors is offered. Single-crystal diamond is shown to offer superior uniformity of response to incident X-rays, and excellent intensity and position sensitivity. Measurements from single-crystal diamond detectors installed at Diamond Light Source are presented, and their use in feedback routines in order to stabilise the X-ray beam at the sample point is discussed.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG14  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
MOPG15 BPM Electronics for the ELBE Linear Accelerator - a Comparison 75
  • U. Lehnert, A. Büchner, B. Lange, R. Schurig, R. Steinbrück
    HZDR, Dresden, Germany
  The ELBE linear accelerator supports a great variety of possible beam options ranging from single bunches to 1.6 mA CW beams at 13 MHz bunch repetition rate. Accordingly high are the dynamic range requirements for the BPM system. Recently, we are testing the Libera Spark EL electronics to supplement our home-built BPM electronics for low repetition rate operation. Here, we discuss the advantages and disadvantages of the two completely different detection schemes. For integration of the Libera Spark EL into our accelerator control system we are implementing an OPC-UA server embedded into the device. The server is based on the free Open62541 protocol stack which is available as open source under the LGPL.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG15  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
MOPG17 Performance Test of the Next Generation X-Ray Beam Position Monitor System for the APS Upgrade 78
  • B.X. Yang, Y. Jaski, S.H. Lee, F. Lenkszus, M. Ramanathan, N. Sereno, F. Westferro
    ANL, Argonne, Illinois, USA
  Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source is developing its next major upgrade (APS-U) based on the multi-bend achromat lattice. Improved beam stability is critical for this upgrade and will require keeping short-time beam angle change below 0.25 μrad and long-term angle drift below 0.5 micro-radian. A reliable white x-ray beam diagnostic system in the front end is a key part of the planned beam stabilization system for the APS-U. This system includes an x-ray beam position monitor (XBPM) based on x-ray fluorescence (XRF) from two specially designed GlidCop A-15 absorbers, a second XBPM using XRF photons from the Exit Mask, and two white beam intensity monitors using XRF from the photon shutter and Compton-scattered photons from the front end beryllium window. We present orbit stability data for the first XBPM used in the feedback control during user operations, as well as test data from the second XBPM and the intensity monitors. The data demonstrated that the XBPM system meets the APS-U beam stability requirements.
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG17  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
MOPG25 Industrialisation of Cavity BPMs 98
  • E. Yamakawa, S.T. Boogert, A. Lyapin
    JAI, Egham, Surrey, United Kingdom
  • S. Syme
    FMB Oxford, Oxford, United Kingdom
  The industrialisation project of a cavity beam position monitor (CBPM) has been commissioned aiming at providing reliable and economical CBPM systems for future Free Electron Lasers (FEL) and similar linac-based facilities. The first prototype of a CBPM system was built at Versatile Electron Linear Accelerator (VELA) in Daresbury Laboratory. We report on the measurement results from the first prototype of our system at VELA and current developments of CBPMs, down-converter electronics and DAQ system.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG25  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
Wideband Stripline BPM for Precise Measurements of Internal Bunch Motion in Proton Synchrotrons  
  • T. Toyama
    KEK, Ibaraki, Japan
  • T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  The talk will review the recent progress of the tapered coupler in BPM striplines and its characteristics in terms of time and frequency responses and position sensitivity. Its application to the intra-bunch feedback will be mentioned.  
slides icon Slides TUCL01 [11.822 MB]  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUCL02 Novel Accelerator Physics Measurements Enabled by NSLS-II RF BPM Receivers 294
  • B. Podobedov, W.X. Cheng, Y. Hidaka
    BNL, Upton, Long Island, New York, USA
  • D. Teytelman
    Dimtel, San Jose, USA
  NSLS-II light source has state of the art RF BPM receivers that were designed and built in-house incorporating the latest technology available in the RF, digital, and software domains. The recently added capability to resolve the orbits of multiple bunches within a turn as well as further improvement in transverse positional resolution for single- and few-bunch fills [*] allowed us to perform a number of novel beam dynamics measurements. These include measuring small impedances of vacuum chamber components, and of extremely small (~10-5) current-dependent tune shifts (transverse and synchrotron), as well as obtaining an amplitude-dependent tune shift curve from a single kicker pulse. We are also effectively utilizing our BPMs to decipher the lifetimes of individual bunches and to visualize single bunch instability dynamics. In this paper we review the unique capabilities of NSLS-II BPMs and present examples of beam physics measurements that greatly benefit from them.
* B. Podobedov, W. Cheng, K. Ha, Y. Hidaka, J. Mead, O. Singh, K. Vetter "Single Micron Single-Bunch Turn-by-Turn BPM Resolution Achieved at NSLS-II", in Proc. IPAC'16, Busan, Korea, May 2016, WEOBB01
slides icon Slides TUCL02 [5.788 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUCL02  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUCL03 Measurements of Longitudinal Coupled Bunch Instabilities and Status of New Feedback System 298
  • G. Rehm, M.G. Abbott, A.F.D. Morgan
    DLS, Oxfordshire, United Kingdom
  We have modified the vertical bunch-by-bunch feedback to also provide a longitudinal kick on a separate input. Using our existing drive/damp system and a modulator/amplifier to the required 1.5 GHz we are thus able to characterise the damping rates of all coupled bunch instabilities, while not able to provide feedback. At the same time, we have started the development of a completely new longitudinal feedback system based on commercially available components, providing 500MS/s, 14 bit conversion in and out, powerful Virtex 7 field programmable gate array for digital signal processing and 32GB of on board buffer for recording data. We report on the status of the development and our plans to bring the new system into use.  
slides icon Slides TUCL03 [2.897 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUCL03  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPG01 Beam Based Calibration of a Rogowski Coil Used as a Horizontal and Vertical Beam Position Monitor 302
  • F. Trinkel, F. Hinder, D. Shergelashvili, H. Soltner
    FZJ, Jülich, Germany
  • F. Hinder
    RWTH, Aachen, Germany
  Electric Dipole Moments (EDMs) violate parity and time reversal symmetries. Assuming the CPT-theorem, this leads to CP violation, which is needed to explain the matter over antimatter dominance in the Universe. So far no direct EDM measurement for charged hadrons have been performed. The goal of the JEDI collaboration (Jülich Electric Dipole moment Investigations) is to measure the EDM of charged particles. The measurement of EDMs of charged hadrons can be performed in storage rings by observing a polarization build-up proportional to the EDM. Due to the smallness of the effect many systematic effects leading to a fake build-up have to be studied. A first step on the way for an EDM measurement is the investigation of systematic errors at the storage ring COSY (COoler SYnchrotron). One part of these studies is the control of the beam orbit with high precession. Therefore a concept of new Beam Position Monitors (BPMs) based on magnetic pick-up coils are used. The main advantage of the coil design is the high response to bunched beam frequency signal and the compactness of the coil itself. First measurement results of such a BPM accelerator environment will be presented.  
poster icon Poster TUPG01 [1.827 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG01  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPG02 A Novel Electron-BPM Front End With Sub-Micron Resolution Based on Pilot-Tone Compensation: Test Results With Beam 307
  • G. Brajnik, S. Carrato
    University of Trieste, Trieste, Italy
  • S. Bassanese, G. Cautero, R. De Monte
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  In this paper we present a novel and original four channel front-end developed for a beam position monitor (BPM) system. In this work, we demonstrate for the first time the continuous calibration of the system using a pilot tone for both beam current dependency and thermal drift compensation, eliminating the need for thermoregulation. By using this original approach, we were also able to investigate several odd and well-known behaviours of BPM systems; the influence of important issues, like the non-linearity of ADCs and the gain compression of amplifiers which do affect the reliability of the measurement, have been fully understood. To achieve these results, we developed a new radio frequency front-end that combines the four pick-up signals originated by the beam with a stable and programmable tone, generated within the readout system. The signals from a button BPM of Elettra storage ring, have been acquired with a 16 bit - 160MS/s digitizer controlled by a CPU that evaluates the acquired data and applies the correction factor of the pilot tone. A final resolution equal to 1.0um, on a 20mm average radius vacuum chamber, has been measured with a long-term stability less than 1um.  
poster icon Poster TUPG02 [3.671 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG02  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPG03 Accurate Bunch Resolved BPM System 311
  • F. Falkenstern, F. Hoffmann, J. Kuszynski, M. Ries
    HZB, Berlin, Germany
  Operation with multiple beams stored on different orbits in storage rings as well as beam dynamics studies requires accurate and stable Beam Position Monitor (BPM) measurements for each individual bunch. Analog BPM systems are usually optimized for measuring the closed orbit, i.e. averaging over all buckets and many turns. Therefore no information about the position of individual bunches are supplied. The new bunch resolved BPM electronic, currently under development at HZB, is based on the analysis of RF-signals delivered by a set of four stripline / pick-up electrodes in each beam position monitor. It has a high spatial resolution over a wide range of bunch currents. Using the four well matched (phase and amplitude) bunch induced RF-signals in combination with a low jitter master clock and commercial data acquisition cards allow beam position measurements on a bunch to bunch basis with micrometer resolution. Experimental results obtained at BESSY II and MLS demonstrates the achieved performance of the setup and will be discussed in detail.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG03  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPG04 CERN PS Booster Transverse Damper: 10 kHz - 200 MHz Radiation Tolerant Amplifier for Capacitive PU Signal Conditioning 315
  • A. Meoli, A. Blas, R. Louwerse
    CERN, Geneva, Switzerland
  After connection to the LINAC4, the beam intensity in the PSBooster is expected to double and thus, an upgrade of the head electronics of the transverse feedback BPM is necessary. In order to cover the beam spectrum for an effective transverse damping, the pickup (PU) signal should have a large bandwidth on both the low and high frequency sides. Furthermore, in order to extend the natural low frequency cut-off from 6MHz (50' load) down to the required 10kHz, with no modification of the existing PUs, a high impedance signal treatment is required. The electronic parts should withstand the radiation dose received during at least a year of service. This constraint implies the installation of the amplifier at a remote location. A solution was found inspired by the technique of oscilloscopes' high impedance probes that mitigates the effect of transmission line mismatch using a lossy coaxial cable with an appropriate passive circuitry. A new large bandwidth, radiation tolerant amplifier has been designed. The system requirements, the analysis, the measurements with the present PUs, the design of the amplifier and the experimental results are described in this contribution.  
poster icon Poster TUPG04 [1.030 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG04  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPG05 Simulation of Bunch Length and Velocity Dependence of Button BPMs for Linacs Using CST Particle Studio® 319
  • M.H. Almalki
    KACST, Riyadh, Kingdom of Saudi Arabia
  • P. Forck, T. Sieber, R. Singh
    GSI, Darmstadt, Germany
  At non-relativistic velocities at a proton LINAC, the electromagnetic field generated by the beam has a significant longitudinal component, and thus the time evolution of the signal coupled to the BPM electrodes depends on bunch length and beam velocity. Extensive simulations with the electromagnetic simulation tool CST Studio® were executed to investigate the dependence of the induced BPM signal on different bunch lengths and velocities. Related to the application, the simulations are executed for the button BPM arrangement as foreseen for the FAIR Proton LINAC. These investigations provide the required inputs for the BPM system and its related technical layout such as analogue bandwidth and signal processing electronics. For the BPM electronics, it is important to estimate the contribution of the harmonic used for the data processing. Additionally, the analogue bandwidth of the BPM system is determined from studying the output signal of the button BPM as a function of bunch length at different beam velocities. This contribution presents the results of the simulations and comments on general findings relevant for a BPM layout and the operation of a hadron LINAC.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG05  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPG06 Development Status of a Stable BPM System for the SPring-8 Upgrade 322
  • H. Maesaka
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  • H. Dewa, T. Fujita, M. Masaki, S. Takano
    JASRI, Hyogo, Japan
  A stable and precise BPM system is necessary for the low-emittance upgrade of SPring-8. Key requirements for the BPM system are: 1) long-term stability to maintain the photon beam direction of the beamline well within the intrinsic photon divergence, 2) single-pass resolution better than 100 μm rms for a 100 pC injected bunch for first turn steering in the beam commissioning, and 3) accuracy better than 100 μm rms with respect to aligned quadrupole and sextupole magnet centers to achieve the design performance of the upgraded ring. To realize the demanded stability, the BPM drift should be reduced to 1 μm level. Therefore, we have been pursuing designs to suppress the thermal deformation of a BPM head and its support and to minimize the drifts of BPM electronics and coaxial cables. The investigation results on causes of drifts of the present SPring-8 BPM system are reflected to the design of the new BPM system. A button-type BPM head has been developed*, which can generate sufficient signal to satisfy the required single-pass resolution. We have also been studying the strategies of the alignment, position survey and electric center calibration of the BPM head better than 100 μm.
* M. Masaki et al., in this conference.
poster icon Poster TUPG06 [5.250 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG06  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPG07 Commisioning of Beam Position and Phase Monitors for LIPAc 326
  • I. Podadera, A. Guirao, D. Jiménez-Rey, L.M. Martínez, J. Mollá, A. Soleto, R. Varela
    CIEMAT, Madrid, Spain
  Funding: Work partially supported by the Spanish Ministry of Science and Innovation under project AIC-A-2011-0654 and FIS2013-40860-R
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 BPMs- are placed in each section of the accelerator to ensure a good beam transport and minimize beam losses. LIPAc is presently under installation and commissioning of the second acceleration stage at 5 MeV. In this stage two types of BPMs are used: four striplines to control the position at the Medium Energy Beam Transport line (MEBT), and three striplines to precisely measure the mean beam energy at the Diagnostics Plate. The seven pickups have been installed and assembled in the beamlines after characterization in a wire test bench, and are presently been commissioned in the facility. In addition, the in-house acquisition system has been fully developed and tested in the wire test bench at CIEMAT. In this contribution, the results of the beam position monitors characterization, the tests carried out during the assembly and the first measurements with the electronics system will be reported.
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG07  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPG08 Design of the Transverse Feedback Kicker for ThomX 329
  • M. El Ajjouri, N. Hubert, A. Loulergue, R. Sreedharan
    SOLEIL, Gif-sur-Yvette, France
  • D. Douillet, A.R. Gamelin, D. Le Guidec
    LAL, Orsay, France
  ThomX is a Compton source project in the range of the hard X rays to be installed in 2017. The machine is composed of an injector Linac and a storage ring where an electron bunch collides with a laser pulse accumulated in a FabryPerot resonator. The final goal is to provide an X-rays average flux of 1011÷1013 ph/s. To achieve this target, it is required to install a transverse feedback system to suppress instabilities generated by injection position jitter sources, resistive wall impedance or collective effects. This paper describes the design and simulation studies of the stripline kicker that will be used for the transverse feedback system.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG08  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPG09 Novel Electrostatic Beam Position Monitors With Enhanced Sensitivity 333
  • M. Ben Abdillah
    IPN, Orsay, France
  Beam Position Monitors (BPM) measure the beam transverse position, the beam phase with respect to the radiofrequency voltage, and give an indication on beam transverse shape. Electrostatic BPMs are composed of four electrodes that transduce the associated electromagnetic field to the beam into electrical signal allowing the calculation of the beam parameters mentioned above. During commissioning and/or experiences phases that needs very low beam current; the precision of the BPM measurements is reduced due to the low sensitivity of electrostatic BPM to beam current. This paper addresses the design, the realization and the testing of a new set of electrostatic BPMs with large electrodes. It emphasizes the strong points of these BPMs in comparison with BPMs present in SPIRAL2 facility  
poster icon Poster TUPG09 [0.770 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG09  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPG10 LCLS-1 Cavity BPM Algorithm for Unlocked Digitizer Clock 336
  • T. Straumann, S.R. Smith
    SLAC, Menlo Park, California, USA
  Funding: Work supported by U.S. Department of Energy Contract No. DE-AC02-76SF00515
Cavity BPMs commonly use the fundamental TM010 mode (excited either in the x/y cavity itself or in a separate "reference" cavity) which is insensitive to beam position as a reference signal, not only for amplitude normalization but also as a phase/time reference to facilitate synchronous detection of the signal derived from the position-sensitive TM110 mode. When taking these signals into the digital domain the reference and position signals need to be acquired by a synchronous clock. However, unless this clock is also locked to the accelerating RF, absolute timing information is lost which affects the relative phase between reference and position signals (assuming they are not carefully tuned to the same frequency). This contribution presents a method for estimating the necessary time of arrival information based on the sampled reference signal which is used to make the signal detection insensitive to the phase of the digitizer clock. Running an unlocked digitizer clock allows for considerable simplification of infrastructure (cabling, PLLs) and thus decreases cost and eases maintenance.
poster icon Poster TUPG10 [1.100 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG10  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPG12 Design for the Diamond Longitudinal Bunch-by-Bunch Feedback Cavity 340
  • A.F.D. Morgan, G. Rehm
    DLS, Oxfordshire, United Kingdom
  In 2017 it is planned to install some additional normal conducting cavities into the Diamond storage ring. In order to deal with the potential higher order modes in these we are designing a longitudinal bunch-by-bunch feedback system. This paper will focus on the design of the overloaded cavity kicker, adapted to the Diamond beam pipe cross section. The design has evolved in order to reduce the strong 3rd harmonic resonance seen on the introduction of the racetrack beam pipe. Through a combination of geometry optimisation and the addition of integrated taper transitions this harmonic has been greatly reduced while also minimising sharp resonances below 15GHz. The major features will be described, as well as the expected performance parameters.  
poster icon Poster TUPG12 [1.423 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG12  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPG13 A New Stripline Kicker for PF-AR Transverse Feedback Damper 344
  • R. Takai, T. Honda, T. Nogami, T. Obina, Y. Tanimoto, M. Tobiyama
    KEK, Ibaraki, Japan
  A feedback damper equipped with a long stripline kicker was used to damp transverse beam oscillation at the Photon Factory Advanced Ring (PF-AR), which is a 6.5-GeV synchrotron radiation source of KEK. Recently, the stripline kicker was renewed to one having shorter electrodes and a smaller loss factor because its insulating support was broken by the beam-induced thermal stress and caused frequent electric discharges inducing dust trapping phenomena. In this paper, we present details of the new stripline kicker, from design to installation, as well as demonstrate results of beam oscillation damping obtained with the new kicker.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG13  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPG15 Intra-Train Position and Angle Stabilisation at ATF Based on Sub-Micron Resolution Stripline Beam Position Monitors 348
  • N. Blaskovic Kraljevic, T. Bromwich, P. Burrows, G.B. Christian, C. Perry, R.L. Ramjiawan
    JAI, Oxford, United Kingdom
  • D.R. Bett
    CERN, Geneva, Switzerland
  A low-latency, sub-micron resolution stripline beam position monitoring (BPM) system has been developed and tested with beam at the KEK Accelerator Test Facility (ATF2), where it has been used to drive a beam stabilisation system. The fast analogue front-end signal processor is based on a single-stage radio-frequency down-mixer, with a measured latency of 16 ns and a demonstrated single-pass beam position resolution of below 300 nm using a beam with a bunch charge of approximately 1 nC. The BPM position data are digitised on a digital feedback board which is used to drive a pair of kickers local to the BPMs and nominally orthogonal in phase in closed-loop feedback mode, thus achieving both beam position and angle stabilisation. We report the reduction in jitter as measured at a witness stripline BPM located 30 metres downstream of the feedback system and its propagation to the ATF interaction point.  
poster icon Poster TUPG15 [1.393 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG15  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPG16 Performance of Nanometre-Level Resolution Cavity Beam Position Monitors and Their Application in an Intra-Train Beam Position Feedback System 352
  • N. Blaskovic Kraljevic, T. Bromwich, P. Burrows, G.B. Christian, C. Perry, R.L. Ramjiawan
    JAI, Oxford, United Kingdom
  • P. Bambade
    LAL, Orsay, France
  • D.R. Bett
    CERN, Geneva, Switzerland
  • S.W. Jang
    Korea University Sejong Campus, Sejong, Republic of Korea
  • T. Tauchi, N. Terunuma
    KEK, Ibaraki, Japan
  A system of three low-Q cavity beam position monitors (BPMs), installed in the interaction point (IP) region of the Accelerator Test Facility (ATF2) at KEK, has been designed and optimised for nanometre-level beam position resolution. The BPMs have been used to provide an input to a low-latency, intra-train beam position feedback system consisting of a digital feedback board and a custom stripline kicker with power amplifier. The feedback system has been deployed in single-pass, multi-bunch mode with the aim of demonstrating intra-train beam stabilisation on electron bunches of charge ~1 nC separated in time by c. 220 ns. The BPMs have a demonstrated resolution of below 50 nm on using the raw measured vertical positions at the three BPMs, and has been used to stabilise the beam to below the 75 nm level. Further studies have shown that the BPM resolution can be improved to around 10 nm on making use of quadrature-phase signals and the results of the latest beam tests will be presented.  
poster icon Poster TUPG16 [1.496 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG16  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPG17 Design and Beam Test Results of the Reentrant Cavity BPM for the European XFEL 356
  • C. Simon, M. Luong, O. Napoly
    CEA/DSM/IRFU, France
  • N. Baboi, D. Lipka, D. Nölle, G. Petrosyan
    DESY, Hamburg, Germany
  • R. Baldinger, B. Keil, G. Marinkovic, M. Roggli
    PSI, Villigen PSI, Switzerland
  • M. Baudrier
    CEA/DRF/IRFU, Gif-sur-Yvette, France
  • L. Maurice
    CEA/IRFU, Gif-sur-Yvette, France
  The European X-ray Free Electron Laser (E-XFEL) will use reentrant beam position monitors (BPMs) in about one quarter of the superconducting cryomodules. This BPM is composed of a radiofrequency (RF) reentrant cavity with 4 antennas and an RF signal processing electronics. Hybrid couplers, near the cryomodules, generate the analog sum and difference of the raw pickup signals coming from two pairs of opposite RF feedthroughs. The resulting sum (proportional to bunch charge) and difference signals (proportional to the product of position and charge) are then filtered, down-converted by an RF front-end (RFFE), digitized, and digitally processed on an FPGA board. The task of CEA/Saclay was to cover the design, fabrication and beam tests and deliver these reentrant cavity BPMs for the E-XFEL linac in collaboration with DESY and PSI. This paper gives an overview of the reentrant BPM sys-tem with focus on the last version of the RF front end electronics, signal processing, and overall system performance. Measurement results achieved with prototypes installed at the DESY FLASH2 linac and in the E-XFEL injector are presented.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG17  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPG18 Design Optimization of Button-Type BPM Electrode for the SPring-8 Upgrade 360
  • M. Masaki, H. Dewa, T. Fujita, S. Takano
    JASRI, Hyogo, Japan
  • H. Maesaka, S. Takano
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  The requirements for a BPM system for the SPring-8 upgrade are long-term stability, sufficient signal intensity and high accuracy*. The design of a button-type electrode for the BPM has been optimized from the perspectives of 1) mechanical structure, 2) rf characteristics, 3) thermal issue. We have adopted the electrode structure without a sleeve enclosing the button to maximize the button diameter for the narrow aperture of the vacuum chamber. The absence of an annular slot around the sleeve in a lodging hole for the electrode eliminates the associated beam impedance. To minimize the beam impedance and the trapped mode heating of the electrode, the rf structure has been optimized by 3D electro-magnetic simulations. To suppress the ohmic loss on the button and center pin thermally isolated from the water cooled BPM block, we have selected molybdenum as a material with high electric and thermal conductivities. The reduction of the heating suppresses thermal deformation of the electrode and the BPM block, and improves thermal stability of the BPM system. The mechanical tolerance of the electrode was defined to fit the error budget for the total BPM offset error of 0.1 mm rms.
* H. Maesaka et al., in this conference.
poster icon Poster TUPG18 [1.104 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG18  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPG26 COSY BPM Electronics Upgrade 383
  • C. Böhme, A.J. Halama, V. Kamerdzhiev
    FZJ, Jülich, Germany
  The Cooler Synchrotron COSY delivers proton and deuteron beams to the users since the early 90s. The experiments are carried out using the circulating beam as well as the beams extracted from the ring and delivered by three beamlines. The original BPM system still operational in the ring does not fulfill the requirements for new experiments. It utilizes cylindrical and shoe-box type diagonally cut capacitive pick-ups. The most signal processing is done the analog way. Additionally to its age and the increasing failure rate, the analog processing introduces large drifts in e.g. the offset, which regularly require a significant effort for manual calibration. Even then the drifts render it impossible to match the requirements of the planned JEDI experiment, which is an orbit with a maximum of 100 um RMS deviation. Therefore an upgrade of the readout electronics was decided. The decision process is described, the implications listed and the current status is reported.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG26  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPG01 Numerical Comparative Study of BPM Designs for the HESR at FAIR 608
  • A.J. Halama, C. Böhme, V. Kamerdzhiev, F. Klehr, S. Srinivasan
    FZJ, Jülich, Germany
  The institute of Nuclear Physics 4(IKP-4) of the Research Center Jülich (FZJ) is in charge of building and commissioning the High Energy Storage Ring (HESR) within the international Facility for Antiproton and Ion Research (FAIR) at Darmstadt. Simulations and numerical calculations were performed to characterize the BPM pickup design that is currently envisaged for the HESR, i.e. a diagonally cut cylindrical pickup. The equivalent circuit has been studied with emphasis on capacitive cross coupling. Based on our findings, performance increasing changes could be introduced. A prototype BPM was constructed and tested on a test bench. A comparison of results is presented. Another proposed design was characterized, as a symmetric coupling behavior is expected. That is a symmetrical straight four-strip geometry. Additionally an extensive study was conducted to see effects due to manufacturing tolerances. Driven by curiosity an eight-strip design was considered, which would allow for beam size measurements. First results for this configuration are shown. Used methodology, tools and results of expected signal level and sensitivity distributions are presented as well.  
poster icon Poster WEPG01 [2.172 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG01  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPG02 Commissioning of the Bunch-by-Bunch Transverse Feedback System for the TPS Storage Ring 612
  • Y.-S. Cheng, K.T. Hsu, K.H. Hu, C.H. Huang, C.Y. Liao
    NSRRC, Hsinchu, Taiwan
  TPS finish its Phase II commissioning in December of 2015 after installation of two superconducting RF cavities and ten sets of insertion devices in mid-2015. Storage beam current up to 520 mA was achieved. Intensive insertion devices commissioning were performed in March 2016 and delivery beam for beam-line commissioning and perform pilot experiments. One horizontal stripline kicker and two vertical stripline kickers were installed in May 2015. Bunch-by-bunch feedback system were commissioning in late 2015. Commercial available feedback processor was selected for the feedback system integration. Beam property and performance of the feedback system were measured. Results will summary in this report.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG02  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPG03 HOM Characterization for Beam Diagnostics at the European XFEL Injector 616
  • N. Baboi, T. Hellert, L. Shi, T. Wamsat
    DESY, Hamburg, Germany
  • R.M. Jones, N.Y. Joshi, L. Shi
    UMAN, Manchester, United Kingdom
  • N.Y. Joshi
    University of Manchester, Manchester, United Kingdom
  Funding: The work is part of EuCARD-2, partly funded by the European Commission, GA 31245.
Higher Order Modes (HOM) excited by bunched elec-tron beams in accelerating cavities carry information about the beam position and phase. This principle is used at the FLASH facility, at DESY, for beam position monitoring in 1.3 and 3.9 GHz cavities. Dipole modes, which depend on the beam offset, are used. Similar monitors are now under design for the European XFEL. In addition to beam position, the beam phase with respect to the accelerating RF will be monitored using monopole modes from the first higher order monopole band. The HOM signals are available from two couplers installed on each cavity. Their monitoring will allow the on-line tracking of the phase stability over time, and we anticipate that it will improve the stability of the facility. As part of the monitor designing, the HOM spectra in the cavities of the 1.3 and 3.9 GHz cryo-modules installed in the European XFEL injector have been measured. This paper will present their dependence on the beam position. The variation in the modal distribution from cavity to cavity will be discussed. Based on the results, initial phase measurements based on a fast oscilloscope have been made.
poster icon Poster WEPG03 [3.281 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG03  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPG05 Design of Stripline Beam Position Monitors for the ESS MEBT 620
  • S. Varnasseri, I. Bustinduy, A. Ortega, I. Rueda, A. Zugazaga
    ESS Bilbao, Zamudio, Spain
  • R.A. Baron, H. Hassanzadegan, A. Jansson, T.J. Shea
    ESS, Lund, Sweden
  There will be overall 8 Beam Position Monitors (BPM) installed in MEBT of ESS. Seven of them will be used for the measurement of beam position, phase and intensity. One BPM will be used for the fast timing characterization of the chopped beam. The design is based on shortened stripline to accommodate the signal level for low velocity proton beam within MEBT read by electronics. Due to mechanical space limits, all the BPMs are embedded inside quadrupoles; which requires special care on the magnetic properties of the materials within BPM sets and in particular the feedthroughs. The prototype electromagnetic and mechanical design is finished and its fabrication is underway. This paper gives an overview of the electromagnetic and mechanical design and related analysis including position signal sensitivity of the BPMs.  
poster icon Poster WEPG05 [1.107 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG05  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPG06 Orbit Feedforward and Feedback Applications in the Taiwan Light Source 623
  • C.H. Kuo, P.C. Chiu, K.T. Hsu, K.H. Hu
    NSRRC, Hsinchu, Taiwan
  Taiwan Light Source (TLS) is a 1.5 GeV third-generation light source with circumference 120 meters. TLS is operated at 360 mA top-up injection mode. The storage ring is 6-fold symmetry with 6-meter straight sections for injection, RF cavity, and insertion devices. There are three undulators were installed in three straight sections to delivery VUV and soft X-ray for users. Beside there undulators, a conventional wiggler (W200 installed at straight sections to provide hard X-ray to serve user. Working parameters of hard X-ray sources are fixed without cause problem on operation. However, undulators should be changing its working parameters during user experiments performed. These undulator during its gap/phase changing will create orbit perturbation due to its field errors. Orbit feedback is main tool to keep orbit without change. However, some correctors setting of the orbit feedback system are easy to saturation due to large perturbation come from U90. To keep functionality of the orbit feedback system working in good condition, combines with orbit feedback and feed-forward is proposed and reported in this conference.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG06  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPG07 A Heterogeneous FPGA/GPU Architecture for Real-Time Data Analysis and Fast Feedback Systems 626
  • M. Vogelgesang, L.E. Ardila Perez, M. Caselle, S.A. Chilingaryan, A. Kopmann, L. Rota, M. Weber
    KIT, Eggenstein-Leopoldshafen, Germany
  We propose a versatile and modular approach for a real-time data acquisition and evaluation system used for monitoring and feedback control in beam diagnostic and photon science experiments. Our hybrid architecture is based on an FPGA readout card* and a GPU for data processing. To increase throughput, lower latencies and reduce overall system strain, the FPGA write data directly in the GPU. After real-time data analysis the GPU writes back results either directly to the FPGA in case of fast feedback systems or to the CPU host system for storage. Communication and scheduling are handled transparently by our processing framework**. However, users can customize and extend it with their own processing plugins. Although the system is designed for real-time purposes, the modular approach also allows standalone usage for high-speed off-line analysis. We evaluated the performance of our solution measuring both processing times of data analysis algorithms used with beam instrumentation detectors as well as transfer times between FPGA and GPU. The latter suggests throughputs of up to 6.5 GB/s with latencies down to tens of microseconds, thus making it suitable for fast feedback systems.
* A PCIe DMA Architecture for Multi-Gigabyte Per Second Data Transmission, 10.1109/TNS.2015.2426877
** A Scalable GPU-based Image Processing Framework for On-line Monitoring, 10.1109/HPCC.2012.116
poster icon Poster WEPG07 [17.144 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG07  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPG08 Fast Orbit Feedback with Linux PREEMPT_RT 630
  • Y.E. Tan
    SLSA, Clayton, Australia
  • D.J. Peake
    The University of Melbourne, Melbourne, Victoria, Australia
  • D.O. Tavares
    LNLS, Campinas, Brazil
  The fast orbit feedback system in development at the Australian Synchrotron aims to improve the stability of the electron beam by reducing the impact of insertion devices and targeting orbit perturbations at the line frequency (50 Hz, 100 Hz and 300 Hz). The system is designed to have a unity gain at a frequency greater than 300 Hz with a simple PI controller with harmonic suppressors in parallel (as was done at Elettra). With most of the system in place (position aggregation, power supplies and corrector coils) we decided to implement a PC based feedback system to test what has been installed as well as the effectiveness of the proposed control algorithms while the firmware for the FPGA based feedback processor is being developed. This paper will report on effectiveness of a feedback system built using a Linux Operating System with the PREEMPT patch running on an Intel CPU.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG08  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPG09 Development of a Prototype Electro-Optic Beam Position Monitor at the CERN SPS 634
  • A. Arteche, A. Bosco, S.M. Gibson
    Royal Holloway, University of London, Surrey, United Kingdom
  • N. Chritin, D. Draskovic, T. Lefèvre, T.E. Levens
    CERN, Geneva, Switzerland
  Funding: Project funded by UK STFC grant, ST/N001583/1
A novel electro-optic beam position monitor capable of rapidly (<50ps) monitoring transverse intra-bunch perturbations is under development for the HL-LHC project. The EO-BPM relies on the fast optical response of two pairs of electro-optic crystals, whose birefringence is modified by the passing electric field of a 1ns proton bunch. Analytic models of the electric field are compared with electromagnetic simulations. A preliminary opto-mechanical design of the EO-BPM was manufactured and installed at the CERN SPS in 2016. The prototype is equipped with two pairs of 5mm cubic LiNbO3 crystals, mounted in the horizontal and vertical planes. A polarized CW 780nm laser in the counting room transmits light via 160m of PM fibre to the SPS, where delivery optics directs light through a pair of crystals in the accelerator vacuum. The input polarization state to the crystal can be remotely controlled. The modulated light after the crystal is analyzed, fibre-coupled and recorded by a fast photodetector in the counting room. Following the recent installation, we present the detailed setup and report the latest status on commissioning the device in-situ at the CERN SPS.
poster icon Poster WEPG09 [8.441 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG09  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPG10 Phase and Energy Stabilization System at the S-Dalinac 638
  • T. Bahlo, C. Burandt, L.E. Jürgensen, T. Kürzeder, N. Pietralla, J. Wissmann
    TU Darmstadt, Darmstadt, Germany
  • F. Hug
    IKP, Mainz, Germany
  The Superconducting Darmstadt Linear Accelerator S‑DALINAC is a recirculating electron accelerator with a design energy of 130 MeV operating in cw. Before entering the 30 MeV main accelerator the low energetic electron beam passes both a normal-conducting injector beamline preparing the beam's 3 GHz time structure as well as a superconducting 10 MeV injector beamline for preacceleration. Since the superconducting injector accelerates on-crest while the main accelerator accelerates off-crest the beam phase is crucial for the efficiency of the acceleration process and the minimization of the energy spread. Due to thermal drifts of the normal-conducting injector cavities this injection phase varies by about 0.2 degree over a timescale of an hour. In order to compensate for these drifts, a high level phase controller has been implemented. Additionally a low-energy scraper system has been installed between the injector and main linac in order to lock both the phase and the energy spread at the linac entrance. We will present the hardware for the phase controller, the control algorithm and the scraper setup. A report on measurements showing the effect of both systems will be given.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG10  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPG11 Operation of the Beam Position Monitor for the Spiral 2 Linac on the Test Bench of the RFQ 642
  • P. Ausset, M. Ben Abdillah, F. Fournier
    IPN, Orsay, France
  • S.K. Bharade, G. Joshi, P.D. Motiwala
    BARC, Trombay, Mumbai, India
  • R. Ferdinand, D.T. Touchard
    GANIL, Caen, France
  The SPIRAL2 project is based on a multi-beam superconducting LINAC designed to accelerate 5 mA deuteron beams up to 40 MeV, proton beams up to 33 MeV and 1 mA light and heavy ions (Q/A = 1/3) up to 14.5 MeV/A. The accurate tuning of the LINAC is essential for the operation of SPIRAL2 and requires measurement of the beam transverse position, the phase of the beam with respect to the radiofrequency voltage, the ellipticity of the beam and the beam energy with the help of Beam Position Monitor (BPM) system. The commissioning of the RFQ gave us the opportunity to install a BPM sensor, associated with its electronics, mounted on a test bench. The test bench is a D-plate fully equipped with a complete set of beam diagnostic equipment in order to characterize as completely as possible the beam delivered by the RFQ and to gain experience with the behavior of these diagnostics under beam operation. This paper addresses the first measurements carried with the BPM on the D-plate: intensity, phase, transverse position and ellipticity under 750 keV proton beam operation  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG11  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPG12 A Versatile BPM Signal Processing System Based on the Xilinx Zynq SoC 646
  • R.L. Hulsart, P. Cerniglia, N.M. Day, R.J. Michnoff, Z. Sorrell
    BNL, Upton, Long Island, New York, USA
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A new BPM electronics module (V301) has been developed at BNL that uses the latest System on a Chip (SoC) technologies to provide a system with better performance and lower cost per module than before. The future of RHIC ion runs will include new RF conditions as well as a wider dynamic range in intensity. Plans for the use of electron beams, both in ion cooling applications and a future electron-ion collider, have also driven this architecture toward a highly configurable approach. The RF input section has been designed such that jumpers can be changed to allow a single board to provide ion or electron optimized analog filtering. These channels are sampled with four 14-bit 400MSPS A/D converters. The SoC's ARM processor allows a Linux OS to run directly on the module along with a controls system software interface. The FPGA is used to process samples from the ADCs and perform position calculations. A suite of peripherals including dual Ethernet ports, uSD storage, and an interface to the RHIC timing system are also included. A second revision board which includes ultra-low jitter ADC clock synthesis and distribution and improved power supplies is currently being commissioned.
poster icon Poster WEPG12 [4.839 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG12  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPG15 A FPGA Based Common Platform for LCLS2 Beam Diagnostics and Controls 650
  • J.C. Frisch, R. Claus, J.M. D'Ewart, G. Haller, R.T. Herbst, B. Hong, U. Legat, L. Ma, J.J. Olsen, B.A. Reese, R. Ruckman, L. Sapozhnikov, S.R. Smith, T. Straumann, D. Van Winkle, J.A. Vásquez, M. Weaver, E. Williams, C. Xu, A. Young
    SLAC, Menlo Park, California, USA
  Funding: work supported by Department of Energy contract DE-AC02-76SF00515
The LCLS2 is a CW superconducting LINAC driven X-ray free electron laser under construction at SLAC. The high beam rate of up to 1MHz, and ability to deliver electrons to multiple undulators and beam dumps, results in a beam diagnostics and control system that requires real time data processing in programmable logic. The SLAC Technical Innovation Directorate has developed a common hardware and firmware platform for beam instrumentation based on the ATCA crate format. The FPGAs are located on ATCA carrier cards, front ends and A-D / D-A are on AMC cards that are connected to the carriers by high speed serial JESD links. External communication is through the ATCA backplane, with interlocks and low frequency components on the ATCA RTM. This platform is used for a variety of high speed diagnostics including stripline and cavity BPMs.
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG15  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPG16 The SLAC LINAC LLRF Controls Upgrade 654
  • D. Van Winkle, J.M. D'Ewart, J.C. Frisch, B. Hong, U. Legat, J.J. Olsen, P. Seward, J.A. Vásquez
    SLAC, Menlo Park, California, USA
  Funding: Work supported by Department of Energy contract DE-AC02-76SF00515
The low level RF control for the SLAC LINAC is being upgraded to provide improved performance and maintainability. RF control is through a high performance FPGA based DDS/DDC system built on the SLAC ATCA common platform. The klystron and modulator interlocks are being upgraded, and the interlocks are being moved into a combination of PLC logic and a fast trip system. A new solid state sub-booster amplifier will eliminate the need for the 1960s vintage high RF phase shifters and attenuators.
poster icon Poster WEPG16 [12.133 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG16  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
  • L.W. Lai, F.Z. Chen, Z.C. Chen, Y.B. Leng, Y.B. Yan, W.M. Zhou
    SSRF, Shanghai, People's Republic of China
  • J. Chen
    SINAP, Shanghai, People's Republic of China
  Funding: Work supported by National Natural Science Foundation (No.11305253, 11575282)
During the past several years a digital BPM (DBPM) processor has been developed at the SINAP. After continuous development and optimization, the processor has been finalized and has come to batch application on the signal processing of cavity BPMs and stripline BPMs at the Dalian Coherent Light Source (DCLS) and the Shanghai Soft X-ray FEL (SXFEL). Tests have been done to evaluate the performances, such as the noise level, the SNR and the cross talk. The system resolution of the cavity and stripline BPMs can achieve 1um and 10um respectively. The test results on the Shanghai Deep-Ultra-Violet (SDUV) and the DCLS will be introduced.
poster icon Poster WEPG17 [6.500 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG17  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPG18 Cavity BPM System for DCLS 661
  • J. Chen, J. Chen, L.W. Lai, Y.B. Yan, L.Y. Yu, R.X. Yuan
    SINAP, Shanghai, People's Republic of China
  • Y.B. Leng
    SSRF, Shanghai, People's Republic of China
  Dalian Coherent Light Source (DCLS) is a new FEL fa-cility under construction in China. Cavity beam position monitor (CBPM) is employed to measure the transverse position with a micron level resolution requirement in the undulator section. The design of cavity, RF front end and data acquisition (DAQ) system will be introduced in this paper. The preliminary measurement result with beam at Shanghai Deep ultraviolet (SDUV) FEL facility will be addressed as well.  
poster icon Poster WEPG18 [2.962 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG18  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPG78 BPM Based Optics Correction of the Solaris 1.5 GeV Storage Ring 836
  • A. Kisiel, P.B. Borowiec, P.P. Goryl, M.B. Jaglarz, M.P. Kopeć, A.M. Marendziak, S. Piela, P.S. Sagalo, M.J. Stankiewicz, A.I. Wawrzyniak
    Solaris, Kraków, Poland
  The Solaris is a novel approach for the third generation synchrotron light sources. The machine consists of 600 MeV linear injector and 1.5 GeV storage ring based on 12 compact Double Bend Achromat (DBA) magnets designed in MAX-IV Laboratory in Sweden. After the commissioning phase of the Solaris storage ring the optimization phase has been started along with the commissioning of the first beamline. An essential part of the beam diagnostics and instrumentation system in the storage ring are Beam Position Monitors (BPMs) based on 36 quarter-wave button BPMs spread along the ring. Proper calibration allowed to measure and correct several beam parameters like closed orbit, tune, chromaticity, dispersion and orbit response matrix. The results of the latest machine optimization including the orbit correction, beam-based alignment and BPM phase advance will be presented.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG78  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
THAL02 Recent Developments for Instability Monitoring at the LHC 852
  • T.E. Levens, K. Łasocha, T. Lefèvre
    CERN, Geneva, Switzerland
  A limiting factor on the maximum beam intensity that can be stored in the Large Hadron Collider (LHC) is the growth of transverse beam instabilities. Understanding and mitigating these effects requires a good knowledge of the beam parameters during the instability in order to identify the cause and provide the necessary corrections. This paper presents the suite of beam diagnostics that have been put into operation to monitor these beam instabilities and the development of a trigger system to allow measurements to be made synchronously with multiple instruments as soon as any instability is detected.  
slides icon Slides THAL02 [15.591 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-THAL02  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)