Title :
Impedance and instabilities in the NLC damping rings
Author :
Corlett, J. ; Li, D. ; Pivi, M. ; Rimmer, Robert ; DeSantis, S. ; Wolski, A. ; Novokhatski, A. ; Ng, C.
Author_Institution :
LBNL, Berkeley, CA, USA
Abstract :
We report on impedance calculations and single-bunch and multi-bunch instabilities in the NLC damping rings. Preliminary designs of vacuum chambers and major components have addressed beam impedance issues, with the desire to increase instability current thresholds and reducing growth rates. MAFIA calculations of short-range and long-range wakefields have allowed computations of growth rates and thresholds, which are presented here. Resistive wall instability dominates long-range effects, and requires a broadband feedback system to control coupled-bunch motion. Growth rates are within the range addressable by current feedback system technologies. Single-bunch instability thresholds are safely above nominal operating current
Keywords :
booster injectors; electron accelerators; particle beam bunching; particle beam stability; storage rings; time-domain analysis; MAFIA calculations; NLC damping rings; beam impedance issues; broadband feedback system; growth rates; impedance calculations; instability current thresholds; long-range wakefields; multi-bunch instabilities; resistive wall instability; short-range wakefields; single-bunch instabilities; thresholds; vacuum chambers; Apertures; Control systems; Damping; Electron beams; Feedback; Impedance; Motion control; Positrons; Radio frequency; Vacuum arcs;
Conference_Titel :
Particle Accelerator Conference, 2001. PAC 2001. Proceedings of the 2001
Conference_Location :
Chicago, IL
Print_ISBN :
0-7803-7191-7
DOI :
10.1109/PAC.2001.987201
