Title :
Commissioning experience with the PEP-II low-level RF system
Author :
Corredoura, P. ; Allison, S. ; Claus, R. ; Ross, W. ; Sapozhnikov, L. ; Schwarz, H.D. ; Tighe, R. ; Yee, C. ; Ziomek, C.
Author_Institution :
Stanford Linear Accel. Center, Stanford Univ., CA, USA
Abstract :
The low-level RF system for PEP-II is a modular design housed in a VXI environment and supported by EPICS. All signal processing and control is done at baseband using in-phase and quadrature (IQ) techniques. Remotely configurable RF feedback loops are used to control coupled-bunch instabilities driven by the accelerating mode of the RF cavities. A programmable DSP based feedback loop is implemented to control DC phase variations across the klystron and to adaptively cancel modulations caused by klystron power supply ripple at selected power line harmonics between 60 Hz and 10 kHz. The system contains a built-in baseband network analyzer which allows remote measurement of the RF feedback loop transfer functions and automated configuration of these loops. This paper presents observations and measured data from the system
Keywords :
accelerator RF systems; commissioning; electron accelerators; feedback; klystrons; network analysers; signal processing; storage rings; DC phase; EPICS; PEP-II; RF feedback loop transfer functions; RF feedback loops; VXI; baseband network analyzer; coupled-bunch instabilities; in-phase; klystron power supply ripple; low-level RF system; power line harmonics; quadrature; signal processing; Acceleration; Automatic control; Baseband; Digital signal processing; Feedback loop; Klystrons; Phase modulation; Process control; Radio frequency; Signal processing;
Conference_Titel :
Particle Accelerator Conference, 1997. Proceedings of the 1997
Conference_Location :
Vancouver, BC
Print_ISBN :
0-7803-4376-X
DOI :
10.1109/PAC.1997.751208
