Title :
Impedance analysis of the PEP-II vacuum chamber
Author :
Ng, C.K. ; Weiland, T.
Author_Institution :
Stanford Linear Accel. Center, Stanford Univ., CA, USA
Abstract :
The PEP-II high energy ring (HER) vacuum chamber consists of a copper tube with periodically spaced pumping slots. The impedance of the vacuum chamber due to the slots is analyzed. Both narrow-band and broad-band impedances are considered as well as longitudinal and transverse components thereof. It is found that although the broad-band impedance is tolerable, the narrow-band impedance may exceed the instability limit given by the natural damping with no feedback system on. Traveling wave modes in the chamber are the major source of this high value narrow-band impedance. We also study the dependences of the impedance on the slot length and the geometrical cross section
Keywords :
accelerator cavities; damping; electric impedance; electron accelerators; particle beam stability; storage rings; PEP-II high energy ring; PEP-II vacuum chamber; broad-band impedances; copper tube; feedback system; geometrical cross section; impedance; instability limit; narrow-band impedances; natural damping; periodically spaced pumping slots; traveling wave modes; Acceleration; Frequency domain analysis; Impedance; Inductance; Joining processes; Laser excitation; Narrowband; Periodic structures; Resonance; Storage rings;
Conference_Titel :
Particle Accelerator Conference, 1995., Proceedings of the 1995
Conference_Location :
Dallas, TX
Print_ISBN :
0-7803-2934-1
DOI :
10.1109/PAC.1995.505784
