• K.-B. Liu, P.C. Chiu, K.T. Hsu, K.H. Hu, Y.-C. Lin, I. Liu, Z.-D. Tsai, C.Y. Wu
  NSRRC, Hsinchu

Corrector magnets of TLS storage ring are served with linear power supplies (corrector magnet power supplies), with some modifications the long-term output current stability and ripple of these linear power supplies were improved from 500 ppm to 50 ppm. But these linear power supplies are very low efficiency、low power factor and about 20Hz low frequency response bandwidth that waste power、noisy and unable to serve fast orbit correction. MCOR30 is a modular switching power converter with smaller volume、high efficiency and above 100Hz frequency response bandwidth, replacing these linear power supplies with MCOR30s that could save power and increasing orbit correction response.

• P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Kuo, C.Y. Wu
  NSRRC, Hsinchu

After commissioning of new BPM system in the TLS, it would support functionality of turn by turn data which can be applied in independent component analysis (ICA). This data analysis method is a special case of blind source separation to separate multivariable signal and additive noise and shown to be a useful diagnostic tool in acceleration application. In this paper, we use the ICA method to analyze experimental BPM turn by turn data of the TLS storage ring, measure betatron tunes, and identify abnormal BPM signals. Other possible applications have been also further studied continuously.

• P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Kuo, C.Y. Wu
  NSRRC, Hsinchu

Since the diagnostic system built with the new BPM system upgrade in TLS, we can observe and analyze the orbit stability more clearly and systematically. The disturbances to cause orbit fluctuation mainly come from power supply ripple, ground vibration, ID effects and etc. Removing the disturbed source is a straight, effective but inactive solution. Orbit feedback system is therefore adopted to suppress the remaining noise. In this report, we will evaluate the orbit stability in TLS and present the efforts we have done to improve the orbit stability.

• K.H. Hu, Y.-T. Chang, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, C.H. Kuo, C.Y. Wu
  NSRRC, Hsinchu

Beam qualities include orbit stability and multi-bunch instability plays a crucial role for the operation of a synchrotron light source. To improve and to keep high beam quality, intensive correlation analysis is performed between data taken by electron BPMs and photon monitors. Efforts of this study will be summary in this report.

• C.H. Kuo, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, D. Lee
  NSRRC, Hsinchu

Commissioning of new digital BPM system for TLS is done recently. The new BPM system could support functionalities of turn by turn data, post-mortem and 10Hz slow data acquisition. 10 kHz fast data translation through Liberas grouping mechanism also succeeded to acquire all bpm data and integrate into the orbit feedback system. Various tests are performed systematically to confirm its performance and reliability and will be discussed in this report. We also present the functionalities and infrastructure of the related diagnostic tools. It could record 10 sec orbit data simultaneously via hardware and software event trigger at 10 kHz. Turn by turn and post mortem are also supported through embedded EPICS IOC. More integrated software tools and environment will continue to be developed for future operation.

• C.H. Kuo, J. Chen, P.C. Chiu, K.T. Hsu, K.H. Hu, D. Lee, C.Y. Wu
  NSRRC, Hsinchu

The orbit feedback system of the TLS has been deployed for a decade to stabilize electron closed orbit. As the upgrades of digital bpm electronics and switching power supply, the infrastructure of orbit feedback system has also been dramatically modified and rebuilt. The most primary works for the upgrade plan have been done including installation of new bpm and power supply since it was first proposed. After the ordered computer blade ready and the current updated rate raised from 1 kHz to 5 kHz or even 10 kHz, the system will evolve to a newly fast orbit feedback system. It is new scheduled to be commissioned in 2009 spring and can be expected to achieve a submicron stability of the electron beam at a bandwidth of at least 60 Hz.