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Hu, K. H.

Paper Title Page
MOPAN092 Earth Leakage Problem of Superconductor Magnet System at TLS 377
  • Y.-C. Chien, K. H. Hu, K.-B. Liu, H. M. Shih
    NSRRC, Hsinchu
  Due to the inherent connection structure between the power supplies and the superconducting magnetic coil, the power supplies are seeing each others as loads through the coil. It has been observed in the pilot test at TLS that there is about 300mA earth leakage current flowing through the earth leakage protection circuit, which presented an interlock and halted the whole system down. The existance of earth leakage current may undermine the overall system stability and pose more threat on the electronic system safety. In this paper, the earth leakage mechanisms are throughly examined and measures to conqure the problem are proposed.  
MOPAN094 Operation Experiences of the Bunch-by-Bunch Feedback System for TLS 383
  • K. T. Hsu, J. Chen, P. C. Chiu, S. Y. Hsu, K. H. Hu, C. H. Kuo, D. Lee
    NSRRC, Hsinchu
  Severe multi-bunch instabilities are bothered the operation of Taiwan Light Source (TLS) during the operation during 2004 just after SRF system upgrade. FPGA-based bunch-by-bunch feedback system was commissioning during late 2005 and early 2006. Multi-bunch instability in both transverse plans and longitudinal are well control. Delivery up to 400 mA stored beam was demonstrated. Transverse feedback system make low chromaticity operation is possible; this is very helpful to improve injection efficiency which are essential for routine top-up operation. Operation experiences of the bunch-by-bunch feedback system will be summary in this report.  
TUPMN074 Improvements to the Injection Efficiency at the Taiwan Light Source 1091
  • Y.-C. Liu, H.-P. Chang, J. Chen, P. J. Chou, K. T. Hsu, K. H. Hu, C. H. Kuo, C.-C. Kuo, K.-K. Lin, G.-H. Luo, M.-H. Wang
    NSRRC, Hsinchu
  Taiwan light source started the 200 mA top-up operation in October 2005, and the stored beam current was subsequently ramped up to 300 mA top-up operation. In the early phase of top-up operation, the injection efficiency had large variation at different machine condition. We have developed the procedures to maintain the injection efficiency. These optimization procedures will be activated whenever the injection efficiency degrades during the top-up operation of TLS.  
FRPMN081 A Preliminary Study of Beam Instabilities in Top-up Operation at Taiwan Light Source 4246
  • P. J. Chou, H.-P. Chang, K. T. Hsu, K. H. Hu, C.-C. Kuo, G.-H. Luo, M.-H. Wang
    NSRRC, Hsinchu
  The storage ring of Taiwan Light Source started to operate fully in top-up mode since October 2005. The beam current has been gradually increased to 300 mA in routine user operation. Phenomena of collective effects were observed at 300 mA in top-up operation mode. Active feedback systems were implemented to stabilize the beam in top-up mode. Results of beam observation and analysis will be presented.  
FRPMN082 Diagnostic and Timing Supports for Top-Up Injection Operation for the TLS 4252
  • J. Chen, P. C. Chiu, K. T. Hsu, S. Y. Hsu, K. H. Hu, C. H. Kuo, D. Lee, C.-J. Wang, C. Y. Wu
    NSRRC, Hsinchu
  Routine top-up operation of Taiwan Light Source (TLS) was started from October 2005 after high efficiency multi-bunch instabilities suppression system put into service. To support the top-up operation, various diagnostics and timing supports are needed. These include diagnostics for injection efficiency, filling pattern of the storage ring, tune, instability, loss pattern measurement. Timing control of the injection process are also needed. Design consideration and details of these efforts will be summary in this report. Further possible improvement will be also discussed.  
FRPMN083 RF Feed-Forward Control Experiments for the 50 MeV Linear Accelerator at TLS 4258
  • K. H. Hu, K. T. Hsu, J.-Y. Hwang, D. Lee, K.-K. Lin, C. Y. Wu
    NSRRC, Hsinchu
  Performance of an electron linear accelerator is very important for synchrotron light source application. Its performance will decide the reproducibility of filling pattern in the booster synchrotron. The filling pattern of the booster synchrotron will affect filling pattern control of the storage ring. The RF feed-forward control can improve performance of linear accelerator deistically. Design consideration and details of the implementation will be summary in this report.  
FRPMN084 Beam Trip Event Diagnostic System for the TLS 4264
  • K. H. Hu, J. Chen, K. T. Hsu, C. H. Kuo, C. Y. Wu
    NSRRC, Hsinchu
  The beam trip event diagnostic system includes several eight channels high-speed digitizer for data acquisition, PC base computer and optical fibre network applies to capture data. The PC are also to serve signal processing, beam trip event analysis and archive. This system can integrate beam trip, interlock signal of SRF, waveform of the injection kicker, quench and interlock signal of the superconducting insertion device, and instability of the stored beam. This diagnostic system can be routine monitor signal and record beam trip event. Design consideration and details of the implementation will be summarized in this report.  
FRPMN085 Application of the IEEE-1394 and the GigE Vision Digital Cameras for Diagnostics in Taiwan Light Source 4270
  • C. H. Kuo, J. Chen, K. T. Hsu, S. Y. Hsu, K. H. Hu, D. Lee, C.-J. Wang, C. Y. Wu
    NSRRC, Hsinchu
  Digital camera has been adopted for the booster, storage ring and transport-line diagnostic recently at the Taiwan Light Source. The system provides low image distortion and lossless image transmission over long distances. The system is integrated with commercial software in the control system. The fully remote control supports various operations and application that is useful. These applications include of screen monitor equip in the booster and storage ring, wider dynamic range sensor and highly flexibility control for the emittance measurement in the transport line, booster and linac. System configuration and present status will be summarized in this report.  
FRPMN086 Beam Position Monitoring System Upgrade for the TLS 4276
  • C. H. Kuo, J. Chen, P. C. Chiu, K. T. Hsu, K. H. Hu
    NSRRC, Hsinchu
  Taiwan light source (TLS) equips with 59 beam position monitors (BPM). Existing Bergos's type multiplexing BPM electronics are working well during last decade. To improve the functionality of the BPM system, new type of BPM electronics (Liberal Electron) will be replace some existing multiplexing BPM electronics. Seamless integration of two kinds of electronics is via reflective memory. The high precision closed orbits were measured by multiplexing BPM via multi-channel PMC form factor 16-bits ADC modules and gigabit Ethernet fast access channel of Libera Electron. Turn-by-turn beam position measurement is also supported by new BPM electronics. Tune measurement is also possible by spectra analysis of the turn-by-turn beam position data. The preliminary version of the orbit data was sampled every millisecond. Fast orbit data were shared by reflective memory network to support fast orbit feedback application. Averaged data were updated to control database at a rate of 10 Hz. The system structure, software environment and preliminary beam test of the BPM system are summarized in this report.