A coupled-bunch ion instability in the SLC electron damping ring

Author

Krejcik, P.

Author_Institution

Linear Accel. Center, Stanford Univ., CA, USA

Volume

2

fYear

1997

fDate

12-16 May 1997

Firstpage

1623

Abstract

Under abnormally poor vacuum conditions in the electron damping ring, described in a companion paper at this conference, an emittance blowup was observed related to a transverse instability. The instability was only observed with two bunches in the ring, and could not be seen with single bunch operation, even at the same total beam current as for the two bunches. Measurements of the transverse beam transfer function indicate strong coupling between the two bunches when ions are present. This is described in terms of a simple model where the oscillating ion cloud provides the coupling between the two bunches. The frequency shift due to coupling can also cause the ion cloud to become unstable, and disappear, when the betatron tune of the electron bunch is just below the 1/2 integer

Keywords

electron accelerators; linear colliders; particle beam bunching; particle beam stability; storage rings; SLC electron damping ring; Stanford Linear Collider; abnormally poor vacuum conditions; betatron tune; bunch operation; coupled-bunch ion instability; emittance blowup; oscillating ion cloud; transverse beam transfer function; transverse instability; Clouds; Contamination; Damping; Electron emission; Frequency; Linear accelerators; Optical coupling; Pollution measurement; Stripline; Transfer functions;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 1997. Proceedings of the 1997

Conference_Location

Vancouver, BC

Print_ISBN

0-7803-4376-X

Type

conf

DOI

10.1109/PAC.1997.750779

Filename

750779