Chung, F.-T.

Paper	Title	Page
WEPMA071	The Design, Fabrication and Performance Testing of the Analog I/Q RF Control System at NSRRC	422
	M.-S. Yeh, L.-H. Chang, F.-T. Chung, Y.-H. Lin, Ch. Wang NSRRC, Hsinchu
	An analog low-level RF system, based on an I/Q modulator and demodulator, has been tested at NSRRC. The I/Q RF control system has the same function blocks as the digital low-level RF system, which we plan to develop for our proposed 3-GeV light source machine. This analog I/Q RF system provides a real function structure to verify the working principle, block functions and performance evaluation of the developing digital low-level RF system. This work presents the designed function diagrams, the measured results for the characteristics of the main RF components, and the performance testing of the analog I/Q RF control system with a dummy cavity.
THYMA03	Commissioning Experience of Superconducting Radio Frequency Systems for the Taiwan Light Source	549
	Ch. Wang, L.-H. Chang, M. H. Chang, S.-S. Chang, F.-T. Chung, F. Z. Hsiao, M.-C. Lin, Y.-H. Lin, M. H. Tsai, T.-T. Yang, M.-S. Yeh NSRRC, Hsinchu
	An industrially manufactured CESR-type SRF module has been routinely operated at the Taiwan Light Source (TLS) at the National Synchrotron Radiation Research Center (NSRRC) since the beginning of March 2005. The original goals of doubling the electron beam current to increase the synchrotron light intensity and of eliminating the instability caused by the interaction of the electron beams with the cavity's higher-order modes have been successfully demonstrated. The greatest challenge to the operational reliability is the shortness of the mean time between failures, and has been successfully overcome. This work reports the commissioning experience of the SRF module at TLS for high beam-current operation toward a maximum beam current of 400 mA in top-up mode from 200 mA in decay mode over last two years. Emphasized will be the instrument development for analysis of SRF trip event and the continuous improvements of the operating analogous low-level rf system against instability of feed back loops caused by heavy beam loading.
	Slides
THPMA051	Cure of Temperature Fluctuations on the Nitrogen-cooled Sections of a CESR-type SRF Module	700
	M.-C. Lin, L.-H. Chang, M. H. Chang, S.-S. Chang, F.-T. Chung, M. H. Tsai, Ch. Wang, T.-T. Yang, M.-S. Yeh NSRRC, Hsinchu
	A strong correlation between tuner motion of the SRF module and the pressure fluctuation of the shielding liquid nitrogen flow is observed. The double elbow waveguide section with nitrogen cooling channels is one of the possible fluctuation sources. Thus it is tested along to investigate the mechanism of pressure and temerature fluctuations, whereas a phase separator with pressure regulation function is used to stabilize the supply pressure of liquid nitrogen. Also it is tried to stabilize the pressure fluctuation by optimizing and regulating the vent flow rate. System setup and primary test results are presented herein.