Energy dispersion compensation and beam loading in X-band linacs for the JLC/NLC

Author

Jones, R.M. ; Dolgashev, V.A. ; Miller, R.H. ; Adolphsen, C. ; Wang, J.W.

Author_Institution

SLAC, Stanford, CA, USA

Volume

4

fYear

2003

fDate

12-16 May 2003

Firstpage

2763

Abstract

The shape of an RF pulse is distorted upon propagating through an X-band accelerator structure due to dispersive effects. This distortion together with beam loading introduce energy spread between 192 bunches. In order to minimize this energy spread we modify the input RF pulse shape. The pulse propagation, energy gain, and beam loading are modelled with a mode-matching computer code and a circuit model. A 2D model and a circuit model of a complete 60 cm structure, consisting of 55 cells and input and output couplers is analyzed. This structure operates with a 5π/6 phase advance per cell. Dispersive effects for this structure are more significant than for previously studied 2π/3 phase advance accelerating structures. Experimental results are compared with the theoretical model and excellent agreement is obtained for the propagation of an RF pulse through the structure.

Keywords

accelerator RF systems; beam handling techniques; electron accelerators; linear colliders; particle beam bunching; 2D model; 5pi/6 phase advance; 60 cm; JLC/NLC; Next Linear Collider/Japanese Linear Collider; RF pulse propagation; X-band accelerator structure; X-band linacs; beam loading; circuit model; distorted RF pulse shape; electron bunches; energy dispersion compensation; energy gain; energy spread; input coupler; mode-matching computer code; output coupler; Acceleration; Circuit simulation; Dispersion; Linear accelerators; Optical reflection; Pulse circuits; Pulse measurements; Pulse shaping methods; Radio frequency; Shape measurement;

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.2003.1289260

Filename

1289260