Simulation Study on Double Diffuser for Loss Reduction in Slow Extraction at J-PARC Main Ring

Ryotaro Muto, Yoshitsugu Arakaki, Takuro Kimura, Akihiko Matsumura, Shigeru Murasugi, Katsuya Okamura, Yoshihisa Shirakabe, Masahito Tomizawa, Eiichi Yanaoka, Lin, Liu (Ed.), Byrd, John M. (Ed.), Regis Neuenschwander (Ed.) (+2 others)
J-PARC (Japan Proton Accelerator Research Complex) Main Ring delivers slow-extracted 30~GeV proton beam to various nuclear and particle physics experiments. In the slow extraction the beam loss at the electrostatic septum (ESS) is inevitable, and the beam loss reduction is a key issue to realize the high-intensity beam delivery. We carried out simulation studies on the effectiveness of the beam diffusers at the upstream of the ESS for the beam loss reduction with various materials and
more » ... of the diffusers. We found out that putting two diffusers simultaneously on the beam was effective for the beam loss reduction, and the expected beam loss was 0.35 times as high as the operation without diffusers. According to the simulation results we installed the diffusers in the J-PARC Main Ring. We performed beam test with one diffuser and beam loss reduction of 60% was observed, which was in good agreement with the simulation results.
doi:10.18429/jacow-ipac2021-wepab192 fatcat:p4kq5h3omng5vn6tqgrsuvz6j4