Title :
Detection of instrumental drifts in the PEP-II LER BPM system
Author :
Wittmer, W. ; Fisher, A.S. ; Martin, D.J. ; Sebek, J.J.
Author_Institution :
SLAC, Menlo Park
Abstract :
During the last PEP-II run a major goal was to bring the Low-Energy Ring optics as close as possible to the design. A large number of BPMs exhibited sudden artificial jumps that interfered with this effort. The source of the majority of these jumps had been traced to the filter-isolator boxes (FIBs) near the BPM buttons. A systematic approach to find and repair the failing units had been developed and implemented. Despite this effort, the instrumental orbit jumps never completely disappeared. To trace the source of this behavior a test setup, using a spare Bergoz MX-BPM processor (kindly provided by SPEAR III at SSRL), was connected in parallel to various PEP-II BPM processors. In the course of these measurements a slow instrumental orbit drift was found which was clearly not induced by a moving positron beam. Based on the size of the system and the limited time before PEP-II closes in Oct. 2008, an accelerator improvement project was initiated to install BERGOZ BPM-MX processors close to all sextupoles.
Keywords :
beam handling techniques; electron optics; particle beam diagnostics; storage rings; Bergoz MX-BPM processor; PEP II LER BPM system; beam position monitor; filter-isolator boxes; instrumental drifts; low-energy ring optics; Electron accelerators; Extraterrestrial measurements; Instruments; Optical design; Optical distortion; Optical feedback; Optical filters; Particle beam optics; Positrons; Testing;
Conference_Titel :
Particle Accelerator Conference, 2007. PAC. IEEE
Conference_Location :
Albuquerque, NM
Print_ISBN :
978-1-4244-0916-7
DOI :
10.1109/PAC.2007.4440089
