コンパクトERL電子ビーム光学系の設計研究

Design study of the compact ERL optics

白神 剛志*; 中村 典雄*; 原田 健太郎*; 島田 美穂*; 坂中 章悟*; 小林 幸則*; 羽島 良一

Shiraga, Takashi*; Nakamura, Norio*; Harada, Kentaro*; Shimada, Miho*; Sakanaka, Shogo*; Kobayashi, Yukinori*; Hajima, Ryoichi

エネルギー回収型リニアック放射光源のための実証機である「コンパクトERL」について、周回軌道の電子ビーム光学系の設計を行った。周回軌道中においてバンチ圧縮を行う構成では、77pCのバンチ電荷に対して、40フェムト秒の超短電子パルスが生成できることを示した。

An energy recovery linac (ERL) is expected to be the next generation synchrotron radiation source that can provide synchrotron radiation of higher brilliance, shorter pulse and higher coherence than the existing third-generation synchrotron light sources. The compact ERL is planned to be constructed in order to solve some problems in achievement of such synchrotron radiation and to confirm advantages of ERLs. We studied and optimized the compact ERL optics to achieve subpico-second bunch generation and efficient energy recovery and to transport the beam to the beam dump without serious beam loss. The design study of the compact ERL optics was done by using the simulation code Elegant. As a result, we succeeded in obtaining a 40-fs bunch with a charge of 77 pC just after the first TBA cell. Furthermore we could suppress the maximum beam size to less than 8.5 mm even after deceleration.