Plasma and Fusion Research

Volume 11, 1404092 (2016)

Regular Articles

Beam Dynamics Analysis of Heavy Ion Injection into the KEK Digital Accelerator
Hiroshi KOBAYASHI1,2), Xinggung LIU2,3), Takashi YOSHIMOTO2,3), Ken TAKAYAMA1,2,3), Tadamichi KAWAKUBO2) and Toshikazu ADACHI2,4)
1)
Tokyo City University, Setagaya, Tokyo 158-8557, Japan
2)
High Energy Accelerator Research Organization/Accelerator Laboratory (KEK), Tsukuba 305-0801, Japan
3)
Tokyo Institute of Technology, Nagatsuda, Midori-ku, Yokohama 226-8503, Japan
4)
The Graduate University for Advanced Studies (SOKENDAI), Hayama, Kanagawa 240-0193, Japan
(Received 14 January 2016 / Accepted 27 March 2016 / Published 30 June 2016)

Abstract

An electrostatic kicker is used for heavy ion beam injection into the KEK digital accelerator (DA) ring. A voltage of 20 kV, which must be immediately turned off after injection, is applied across the electrostatic electrodes before injection so as to deflect the injected beam into the ring orbit. An SI-Thyristor Matrix Array (SI-Thy MA) has been developed to replace the conventional thyratron switching device. Long ringing in the turn-off voltage affects the longitudinal motion of the injected beam bunch, resulting in the formation of microstructure. The physics behind the microstructure formation is discussed in detail.

Keywords

KEK-DA, SI-Thyristor Matrix Array, longitudinal beam dynamics, space charge effect, microstructure

DOI: 10.1585/pfr.11.1404092

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