Injection related background due to the transverse feedback

Author

Decker, F.J. ; Akre, R. ; Fisher, A. ; Iverson, R.H. ; Weaver, M.

Author_Institution

SLAC, Stanford, CA, USA

Volume

4

fYear

2003

fDate

12-16 May 2003

Firstpage

2285

Abstract

The background in the BaBar detector is especially high during injection, when most components are actually having reduced voltages. The situation is worse for the beam in high energy ring (HER) when the LER beam is present. It was found that the transverse feedback system plays an important role when stacking more charge on top of existing bunches. Lowering the feedback gain helped and it was realized later that the best scenario would be to gate off the feedback for only the one bunch, which got additional charge injected into it. The explanation is that the blown-up, but centered, original HER bunch plus the small injected off-axis bunch (each with half the charge) would stay in the ring if not touched, but the feedback system sees half the offset and wants to correct it, therefore disturbing and scraping the blown-up part.

Keywords

accelerator RF systems; accelerator cavities; electron accelerators; particle beam bunching; particle beam diagnostics; particle beam injection; storage rings; BaBar detector; PEP II; RF cavity tuner; beam bunches; beam injection; beam position monitor; blown-up bunch; charge injection; charge stacking; feedback gain; high energy ring; injection related background; low energy ring; small injected off-axis bunch; transverse feedback system; Detectors; Feedback; Lattices; Monitoring; Particle beam injection; Photodiodes; Stacking; Synchrotrons; US Department of Defense; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 2003. PAC 2003. Proceedings of the

ISSN

1063-3928

Print_ISBN

0-7803-7738-9

Type

conf

DOI

10.1109/PAC.2003.1289093

Filename

1289093