Stretched bunch shapes in the NSLS VUV ring

Author

Towne, N.

Author_Institution

Nat. Synchrotron Light Source, Brookhaven Nat. Lab., Upton, NY, USA

Volume

4

fYear

1999

fDate

1999

Firstpage

2828

Abstract

For bunches stretched with a higher-harmonic cavity, longitudinal bunch shapes are influenced by small variations in the potential wells of the buckets of the bunch train. This paper discusses three things that perturb the bunch shapes in the NSLS VUV ring: the -90° (non-optimal) phase of the harmonic cavity maintained by the RF controls [1], higher-order modes (HOM) of the main cavity, and the effect of unfilled buckets on the RF fields in the accelerating modes of the two cavities. The suppression of the lowest-lying HOM in an experiment using RF feedback applied to two HOM damping-probe ports is described and results of calculations of the effect of unfilled buckets are given. Measured bunch shapes are shown and discussed

Keywords

accelerator cavities; electron accelerators; particle beam bunching; storage rings; NSLS VUV ring; RF feedback; bunch shape; harmonic cavity; higher-order modes; longitudinal bunch shapes; lowest lying higher-order mode; stretched bunch shapes; unfilled buckets; Acceleration; Damping; Feedback; Laboratories; Light sources; Potential well; Radio frequency; Shape measurement; Synchrotrons; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 1999. Proceedings of the 1999

Conference_Location

New York, NY

Print_ISBN

0-7803-5573-3

Type

conf

DOI

10.1109/PAC.1999.792952

Filename

792952