Control of longitudinal instabilities in the LEB

Author

Grimm, T.L. ; Coleman, P.D.

Author_Institution

Superconducting Super Collider Lab., Dallas, TX, USA

fYear

1993

fDate

17-20 May 1993

Firstpage

3252

Abstract

The potential longitudinal instabilities and their control in the SSC Low Energy Booster are examined. Coasting beam theory shows there is a chance for microwave instabilities at the end of the acceleration period for the maximum design current of 0.5 Adc. The beam is stable to microwave instabilities for the Collider fill current of 0.1 Adc. Single bunch instabilities driven by the RF cavity accelerating mode will be stabilized by beam phase, voltage amplitude, tuner bias and RF feedback loops. The coupled bunch instabilities driven by the cavities´ higher order modes and ether resonant structures appear to represent the biggest challenge to longitudinal stability. A broadband passive damper on each RF cavity will greatly decrease the chance of any coupled bunch instabilities although other options to aid the damper are investigated. The control of longitudinal instabilities in the LEB appears feasible and should not limit its operation up to the peak design intensities

Keywords

beam handling techniques; cavity resonators; particle beam diagnostics; proton accelerators; synchrotrons; LEB; RF cavity accelerating mode; RF feedback loop; SSC Low Energy Booster; beam phase; broadband passive damper; coasting beam theory; higher order modes; instability control; longitudinal instabilities; microwave instabilities; single bunch instabilities; tuner bias; voltage amplitude; Acceleration; Colliding beam devices; Feedback loop; Microwave theory and techniques; Particle beams; Radio frequency; Resonance; Stability; Tuners; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 1993., Proceedings of the 1993

Conference_Location

Washington, DC

Print_ISBN

0-7803-1203-1

Type

conf

DOI

10.1109/PAC.1993.309616

Filename

309616