Tune feed-forward for PEP-II

Author

Decker, F.J. ; Fisher, A. ; Hendrickson, L. ; Krauter, K.E. ; Murphy, B. ; Weathersby, S. ; Wienands, U.

Author_Institution

SLAC Collaboration, Stanford Univ., CA, USA

Volume

5

fYear

2001

fDate

2001

Firstpage

3558

Abstract

The PEP-II B-Factory achieved design performances in 2000. The tune shifts of the rings are already about twice the design numbers of 0.03. This requires constant adjustments from the operators during fills and top-offs. A tune feedback was envisioned first, but the wide, multipeaked tune signals make it tricky even for a human to adjust the tunes correctly. Since tunes are strongly correlated with the currents in the high and low energy rings (HER and LER), a tune feed-forward system was implemented. Each ring uses the measured dependences on its own current of about + or -0.0 18 per Ampere for the x- or y-tune. There is also a provision to adapt to the other beam´s current. This parameter is usually a factor of ten lower. How these parameters change for different scenarios like optimizing the visual tune profile, the luminosity, or the measured single beam tune peak is discussed

Keywords

accelerator RF systems; accelerator control systems; electron accelerators; electron beam focusing; optimisation; particle beam bunching; particle beam dynamics; particle beam stability; storage rings; tuning; HER; LER; PEP-II; beam current; bunches; constant adjustments; feedforward tuning system; fills; high energy rings; low energy rings; optimisation; ring tune shifts; spot sizes; top-offs; visual tune profile; wide multipeaked tune signals; Contracts; Current measurement; Feedforward systems; Force feedback; Frequency conversion; Humans; Linear particle accelerator; Particle measurements; Shape; Sun;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 2001. PAC 2001. Proceedings of the 2001

Conference_Location

Chicago, IL

Print_ISBN

0-7803-7191-7

Type

conf

DOI

10.1109/PAC.2001.988177

Filename

988177