PAC09 - List of Authors (Ko, I.S.)

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Ko, I.S.

Paper	Title	Page
TH6REP070	Development and Commissioning of Bunch-by-Bunch Longitudinal Feedback System for Duke Storage Ring	4117
	W. Wu, M.D. Busch, Y. Kim, J.Y. Li, G. Swift, P. Wang, Y.K. Wu FEL/Duke University, Durham, North Carolina I.S. Ko, I.S. Park PAL, Pohang, Kyungbuk D. Teytelman Dimtel, San Jose
	Funding: work supported by US Air Force Office of Scientific Research medical FEL grant FA9550-04-01-0086 The coupled bunch mode instabilities (CBMIs) caused by vacuum chamber impedance limit and degrade the performance of the storage ring based light sources. A bunch-by-bunch longitudinal feedback (LFB) system has been developed to stabilize beams for the operation of a storage ring based Free Electron Laser (FEL) and the High Intensity Gamma-ray Source (HIGS) at the Duke storage ring. Employing a Giga-sample FPGA based processor (iGP), the LFB is capable of damping out the dipole mode oscillation for all 64 bunches. As a critical subsystem of the LFB system, kicker cavity is developed with a center frequency of 938 MHz, a wide bandwidth (> 90 MHz), and a high shunt impedance (> {10}00 Ω). First commissioned in summer 2008, the LFB has been operated to stabilize high current multi-bunch operation. More recently, the LFB system is demonstrated as a critical instrument to ensure stable operation of the HIGS with a high intensity gamma beam above 20 MeV with a frequent top-off injection to compensate for the substantial and continuous electron beam loss in the Compton scattering process. In the future, we will perform detailed studies of the impedance effects using the LFB system.

Paper

Title

Page

TH6REP070

Development and Commissioning of Bunch-by-Bunch Longitudinal Feedback System for Duke Storage Ring

4117

W. Wu, M.D. Busch, Y. Kim, J.Y. Li, G. Swift, P. Wang, Y.K. Wu
FEL/Duke University, Durham, North Carolina
I.S. Ko, I.S. Park
PAL, Pohang, Kyungbuk
D. Teytelman
Dimtel, San Jose

Funding: work supported by US Air Force Office of Scientific Research medical FEL grant FA9550-04-01-0086

The coupled bunch mode instabilities (CBMIs) caused by vacuum chamber impedance limit and degrade the performance of the storage ring based light sources. A bunch-by-bunch longitudinal feedback (LFB) system has been developed to stabilize beams for the operation of a storage ring based Free Electron Laser (FEL) and the High Intensity Gamma-ray Source (HIGS) at the Duke storage ring. Employing a Giga-sample FPGA based processor (iGP), the LFB is capable of damping out the dipole mode oscillation for all 64 bunches. As a critical subsystem of the LFB system, kicker cavity is developed with a center frequency of 938 MHz, a wide bandwidth (> 90 MHz), and a high shunt impedance (> {10}00 Ω). First commissioned in summer 2008, the LFB has been operated to stabilize high current multi-bunch operation. More recently, the LFB system is demonstrated as a critical instrument to ensure stable operation of the HIGS with a high intensity gamma beam above 20 MeV with a frequent top-off injection to compensate for the substantial and continuous electron beam loss in the Compton scattering process. In the future, we will perform detailed studies of the impedance effects using the LFB system.