THP020  光源加速器  8月6日 小ホール 13:00 - 15:00
Beam Halo Propagation and Mitigation for Beam Loss Study at KEK Compact ERL
○田中 オリガ,中村 典雄,島田 美帆,帯名 崇,高井 良太,宮島 司(高エネルギー加速器研究機構)
○Olga Tanaka, Norio Nakamura, Miho Shimada, Takashi Obina, Ryota Takai, Tsukasa Miyajima (KEK)
Longitudinal and transverse beam halo measurements were evaluated during recent KEK compact ERL (cERL) operation, aiming to increase the beam current up to some uA. As far, the beam current was increased; we expect some essential changes in the beam dynamics issues, such as beam halo formation and propagation. First step towards the stable and safe operation of the machine was longitudinal beam halo measurement. We investigate beam halo originated from characteristics and imperfections of an electron gun system. Then we perform the corresponding start-to-end simulation using the tracking codes GPT (General Particle Tracer) and ELEGANT to apply the beam loss distribution along the beam line. Thus, the impact of collimators was obtained. Transverse beam halo measurement allows the beam halo mitigation. A theoretical estimation based on the core-halo limit theory together with the corresponding simulation give some useful information for beam halo management and, therefore, beam loss reduction. The current results on this topic are presented in this paper.