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Hsu, K.-T.

Paper Title Page
TUPCH095 Status of Synchrotron Radiation Monitor at TLS 1232
 
  • C.H. Kuo, J. Chen, K.-T. Hsu, S.Y. Hsu, K.H. Hu, D. Lee, C.-J. Wang
    NSRRC, Hsinchu
 
  Synchrotron radiation monitor of the Taiwan Light Source have been upgraded recently. Improvement of optics and modelling was performed to improve accuracy of measurement for small beam size. Synchrotron light interferometer is implemented for complementary measurement. IEEE-1394 digital CCD camera is used to improve image transmission quality, camera remote control and to extend dynamic range. Intensify gated camera are included in this upgrade for dynamic property observation of the stored beam. Functionality enhancement of image analysis is also supported. Efforts and achievements will be summarized in this report.  
TUPCH197 Low level RF System Development for the Superconducting Cavity in NSRRC 1477
 
  • M.-S. Yeh, L.-H. Chang, F.-T. Chung, K.-T. Hsu, Y.-H. Lin, C. Wang
    NSRRC, Hsinchu
 
  The present low level system in NSRRC is based on analogy feedback control scheme. It provides feedback regulation on EM field, phase, and resonant frequency of the superconducting RF cavity. In order to address the required flexibility and improve diagnostic of the RF control system, a new digital low-level RF system based on Field Programmable Gate Array (FPGA) is proposed to be develop in house. The status of current analogy low level RF system and the specification of new digital FPGA based low level RF system are reposted herein.  
WEPLS133 Stability Study of Superconductor Magnet Power Supplies at TLS 2688
 
  • Y.-C. Chien, K.-T. Hsu, C.-S. Hwang, C.-Y. Liu, K.-B. Liu
    NSRRC, Hsinchu
 
  In this paper, performance of three power supplies schemes driving the newly-developed Superconducting Wave Length Shifter Magnet at TLS is investigated. Due to the inherent structure of the Superconducting Magnet, the main and two accessory trimming power supplies are physically correlated with each others. Due to the inherent structure, in order to achieve high performance control of the magnet, slew rate control of the main power supply and the proper operation sequence have to be properly managed, otherwise, small current disturbance can occurs, which may disgrade the stability of the performance of Superconducting Magnet.  
THPCH097 Commissioning of the Digital Transverse Bunch-by-bunch Feedback System for the TLS 3020
 
  • K.H. Hu, J. Chen, P.J. Chou, K.-T. Hsu, S.Y. Hsu, C.H. Kuo, D. Lee, C.-J. Wang
    NSRRC, Hsinchu
  • A. Chao
    SLAC, Menlo Park, California
  • K. Kobayashi, T. Nakamura
    JASRI/SPring-8, Hyogo-ken
  • W.-T. Weng
    BNL, Upton, Long Island, New York
 
  Multi-bunch instabilities degrade the beam quality leading to increased beam emittance, energy spread or even to beam loss. The feedback system is used to suppress multi-bunch instabilities due to resistive wall of the beam ducts, cavity-like structures and trapped ions. A new digital transverse bunch-by-bunch feedback system was commissioned at the Taiwan Light Source recently, and has replaced the previous analog system. The new system has the advantages that it enlarges the tune acceptance compared with the old system, enhances damping for transverse instability at high current, and as a result, top-up operation was achieved. In this new system, a single feedback loop simultaneously suppresses both the horizontal and vertical multi-bunch instabilities. The feedback system employs the latest generation FPGA feedback processor to process bunch signals. Memory installed to capture up to 250 msec bunch oscillation signal has included the considerations for system diagnostic and should be able to support various beam physics study.  
THPCH098 FPGA-based Longitudinal Bunch-by-bunch Feedback System for TLS 3023
 
  • C.H. Kuo, J. Chen, P.J. Chou, K.-T. Hsu, S.Y. Hsu, K.H. Hu, W.K. Lau, D. Lee, C.-J. Wang, M.-H. Wang, M.-S. Yeh
    NSRRC, Hsinchu
  • M. Dehler
    PSI, Villigen
  • K. Kobayashi, T. Nakamura
    JASRI/SPring-8, Hyogo-ken
 
  A FPGA Based Longitudinal Bunch-by-Bunch Feedback System for TLS is commissioning recently to suppress strong longitudinal oscillation. The system consists of pickup, Bunch oscillation detector, FPGA based feedback processor borrow form the design of Spring8. Modulator converts the correction signal to the carrier frequency and longitudinal kicker which was re-designed form SLS' and working at 1374 MHz. The feedback processor is based upon latest generation FPGA feedback processor to process bunch signals. The memory capture is up to 250 msec bunch oscillation signal. The software and hardware design are also included for system diagnostic and support various beam physics study. Preliminary commission result will be summaried in this report.  
THPCH144 The Upgrading of the TLS Injector Bumper and Septum Power Supplies for Top-up Operation 3128
 
  • C.-S. Fann, K.-T. Hsu, S.Y. Hsu, J.-Y. Hwang, K.-K. Lin, K.-B. Liu, Y.-C. Liu
    NSRRC, Hsinchu
 
  Due to the inevitable requirement of routine top-up mode operation at TLS (Taiwan Light Source), the reliability of all components in TLS injector has been reevaluated in the past several months. Among all possible subsystems to be reinforced, the bumper and septum power supplies revealed urgent need of upgrading while operated continuously in the user shifts. In this report, the modification of the charging mechanism of the pulsed power supplies is described. The modular feature of the newly built units provides fast replacement capability in case of components failure. The unified specifications for all components have greatly reduced the effort in preparing spare parts. The test results of these units are presented in this report.  
THPCH171 Control System of the Superconducting Insertion Device at TLS 3197
 
  • J. Chen, K.-T. Hsu, S.Y. Hsu, K.H. Hu, C.H. Kuo, D. Lee, C.-J. Wang
    NSRRC, Hsinchu
 
  There are three superconducting insertion devices installed at Taiwan Light Source. Two is under construction. These insertions enhance hard X-ray production to satisfy the research requirement of X-ray community. The control system is implemented to support the operation of all these superconducting insertion devices. The control system coordinate the operation of the main power supply and the trimming power supply to charge/discharge the magnets and provide essential interlock protection for the coils and vacuum ducts. Friendly user interface supports routine operation. Various applications are also developed to aid the operation of these insertion devices. Design consideration and details of the implementation will be summary in this report.  
THPLS066 Improvement on the Single Bunch Operation of the TLS Injector 3439
 
  • J.-Y. Hwang, C.-S. Fann, K.-T. Hsu, S.Y. Hsu, K.H. Hu, S.H. Lee, K.-K. Lin, K.-B. Liu, Y.-C. Liu
    NSRRC, Hsinchu
 
  The improvement of the TLS (Taiwan Light Source) injector on single bunch operation is presented in this study. Limited by the existing design of the TLS injector, the single bunch operation was not optimized in terms of bunch purity for specific users of TLS. A high voltage pulser was implemented to improve the situation. This pulser has been integrated into the high-voltage-deck electronics of electron gun for single bunch generation. Both high-voltage pulses and the associated electron bunches are monitored with a wideband digital oscilloscope. The result shows that the bunch purity can be greatly improved by using the newly installed pulser. It also greatly eliminates the beam losses while injected into the booster ring.  
THPLS067 Vertical Beam Size Control in TLS and TPS 3442
 
  • C.-C. Kuo, H.-P. Chang, J.-R. Chen, P.J. Chou, K.-T. Hsu, G.-H. Luo, H.-J. Tsai, D.-J. Wang, M.-H. Wang
    NSRRC, Hsinchu
  • A. Chao
    SLAC, Menlo Park, California
  • W.-T. Weng
    BNL, Upton, Long Island, New York
 
  Vertical beam size control is an important issue in the light source operations. The horizontal-vertical betatron coupling and vertical dispersion were measured and corrected to small values in the TLS 1.5 GeV storage ring. Estimated beam sizes are compared with the measured values. By employing an effective transverse damping system, the vertical beam blow-up due to transverse coherent instabilities such as the fast-ion beam instability was suppressed and as a result, the light source is very stable. In NSRRC we are designing an ultra low emittance 3-GeV storage ring and its designed vertical beam size could be as small as a few microns. The ground and mechanic vibration effects, and coherent instabilities could spoil the expected photon brightness due to blow-up of the vertical beam size if not well taken care of. The contributions of these effects to vertical beam size increase will be evaluated and the counter measures to minimize them will be proposed and reported in this paper.  
THPLS069 Preliminary Design of the TPS Linac to Booster Transfer Line 3448
 
  • Y.-C. Liu, H.-P. Chang, C.-S. Fann, K.-T. Hsu, S.Y. Hsu, K.-K. Lin, K.-B. Liu, G.-H. Luo
    NSRRC, Hsinchu
 
  The preliminary design of the LTB (linac to booster) transfer line of the proposed TPS (Taiwan Photon Source) project is considered in this study. The layout presented in this report is based on the booster lattice and the choice of linac parameters. These parameters are adopted from previous report of booster design and typical commercial available products of linac. The simulation result indicates that the desired optical functions at a given location can be readily obtained by varying the appropriate focusing strength of quadrupoles. It provides tuning capability to match various possible options of optical functions at injection location. This report is presented together with design consideration of a set of beam diagnostics instruments.