Keyword: kicker
Paper Title Other Keywords Page
MOPG05 Transient Studies of the Stripline Kicker for Beam Extraction from CLIC Damping Rings flattop, impedance, extraction, simulation 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)  
MOPG69 Study of YAG Exposure Time for LEReC RF Diagnostic Beamline electron, diagnostics, simulation, radiation 233
  • S. Seletskiy, T.A. Miller, P. Thieberger
    BNL, Upton, Long Island, New York, USA
  The LEReC RF diagnostic beamline is supposed to ac-cept 250 us long bunch trains of 1.6 MeV ' 2.6 MeV (kinetic energy) electrons. This beamline is equipped with a YAG profile monitor. Since we are interested in observ-ing only the last bunch in the train, one of the possibilities is to install a fast kicker and a dedicated dump upstream of the YAG screen and related diagnostic equipment. This approach is expensive and challenging from an engineer-ing point of view. Another possibility is to send the whole bunch train to the YAG screen and to use a fast gated camera to observe the image from the last bunch only. In this paper we demonstrate the feasibility of the last ap-proach, which significantly simplifies the overall design of the RF diagnostic beamline.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG69  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUAL03 Beam Loss and Abort Diagnostics during SuperKEKB Phase-I Operation hardware, injection, timing, cavity 282
  • H. Ikeda, J.W. Flanagan, H. Fukuma, T. Furuya, M. Tobiyama
    KEK, Ibaraki, Japan
  Beam commissioning of SuperKEKB Phase-I started in Feb., 2016. In order to protect the hardware components of the accelerator against unstable Ampere class beams, the controlled beam abort system was upgraded. Because of the higher beam intensity and shorter beam lifetime than at the original KEKB, a beam abort monitor system is important for machine tuning and the safety of the components. The system collected the data of all aborts of more than 1000 in this operation period, and we diagnosed not only the hardware performance but the tuning software by analyzing the relations between beam current, loss monitor signals and RF cavity voltages. This paper will give the outline of the monitoring system, and will present typical examples of signal and diagnoses.  
slides icon Slides TUAL03 [25.716 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUAL03  
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 feedback, FPGA, damping, interface 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)  
TUPG08 Design of the Transverse Feedback Kicker for ThomX impedance, simulation, feedback, dipole 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)  
TUPG13 A New Stripline Kicker for PF-AR Transverse Feedback Damper impedance, feedback, damping, operation 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 feedback, extraction, monitoring, operation 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 feedback, cavity, factory, electron 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)  
TUPG33 Beam Diagnostics at Siam Photon Source storage-ring, diagnostics, photon, synchrotron 410
  • P. Klysubun, S. Klinkhieo, S. Kongtawong, S. Krainara, T. Pulampong, P. Sudmuang, N. Suradet
    SLRI, Nakhon Ratchasima, Thailand
  In recent years the beam diagnostics and instrumenta-tion of Siam Photon Source (SPS), Thailand synchro-tron radiation facility, have been significantly improved for both the booster synchrotron and the 1.2 GeV stor-age ring. Additional diagnostics have been designed, fabricated, and installed, and the existing systems have been upgraded. This paper describes the current status of the beam diagnostics at SPS, as well as their respec-tive performances. These systems include beam posi-tion monitors (BPMs), a diagnostics beamline, beam loss monitors (BLMs), real-time tune measurement setups, and others. Apart from the instrument hardware, the acquisition electronics along with the processing software have been improved as well. The details of these upgrades are reported herewith.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG33  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPG44 Diagnoses and Controls of Single e-Pulse Extraction at LCLS-I for the ESTB Program extraction, feedback, operation, controls 445
  • J.C. Sheppard, T.G. Beukers, W.S. Colocho, F.-J. Decker, A.A. Lutman, B.D. McKee, T.J. Smith, M.K. Sullivan
    SLAC, Menlo Park, California, USA
  A pulsed magnet is used to kick single electron bunches into the SLAC A-line from the 120 Hz LCLS-1 bunch train. These single bunches are transported to the End Station Test Beam facility. It is mandated that extraction from the LCLS beam does not disturb the non-kicked pulses. An 8 mrad kick is required to extract a bunch; without compensation the following bunch experiences a 2 urad kick; with compensation this kick is reduced to about 0.1 urad which is well within the jitter level of about 0.3 urad. Electron and photon diagnostics were used to identify problems arising from eddy currents, beam feedback errors, and inadequate monitoring and control protocol. This paper discusses the efforts to diagnose, remedy, and control the pulse snatching.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG44  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WECL03 Measurement of the Beam Response to Quadrupole Kick by Using Stripline Pickup Monitor at J-PARC Main Ring quadrupole, resonance, betatron, operation 604
  • Y. Nakanishi, A. Ichikawa, A. Ichikawa, A. Minamino, K.G. Nakamura, T. Nakaya
    Kyoto University, Kyoto, Japan
  • T. Koseki, H. Kuboki, M. Okada, T. Toyama
    KEK, Tokai, Ibaraki, Japan
  Funding: Work supported by MEXT KAKENHI, GA 25105002, Grant-in-Aid for Scientific Research on Innovative Areas titled "Unification and Development of the Neutrino Science Frontier"
In high intensity proton synchrotrons, linear and nonlinear betatron resonances cause beam loss. When the betatron tune spreads over a resonance line, the oscillation amplitude will get larger, causing a large beam loss. Our study aims for a direct measurement of the betatron tune spread by using a quadrupole kicker and a 4-electrode monitor. The monochromatic rf signal is inputted to the kicker and we induce an oscillation by kicking the beam. The amplitude of the quadrupole oscillation will depend on the number of particles having a certain tune. In the beam test at J-PARC MR, the dipole kicker was used as a quadrupole kicker by exciting the two facing electrodes in-phase. We measured the response to the kick at several frequencies. We observed that the amplitude depends on the kicker frequency and the number of particles per bunch. This demonstrates that the quadrupole oscillation can be induced by a kicker and the possibility of measuring the number of a particular tune particle from the response. We will present the result of the beam test and our prospect and the comparison between the experimental result and a numerical calculation.
slides icon Slides WECL03 [2.054 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WECL03  
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 feedback, insertion-device, insertion, vacuum 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)