Radiation Design of New 30 kW Beam Dump of J-PARC Main Ring

Masashi Shirakata, Hironori Kuboki, Junpei Takano, Button, David (Ed.), Tan, Eugene (Ed.), Boland, Mark (Ed.), Tanaka, Hitoshi (Ed.), Schaa, Volker RW (Ed.), Dowd, Rohan (Ed.)
The J-PARC Main Ring (MR) has a beam dump for the beam study and beam abort. Its present capacity is 7.5 kW in one hour average which is limited by radiation condition for the environments. The number of protons in one MR cycle is 2.6·10⁺¹⁴ in recent days, which corresponds to the beam power of 500 kW. As the top energy of J-PARC MR is 30 GeV, the number of available beam shots is restricted to less than twenty in one hour with such an intense beam. It imposes a big limitation on high power
more » ... n on high power beam tuning and study. The number of protons is expected to become 3.3·10⁺¹⁴ for MW operation. Hence, an upgrade of the beam dump from 7.5 kW to 30 kW is planned. The radiation dose rate should be less than 0.25μSv/h on the ground. The backscattered neutron flux should be examined in the accelerator tunnel. The new dump design on radiation matters is described in this paper.
doi:10.18429/jacow-ipac2019-tupts032 fatcat:4axq3f4rgndjdlpkp27npbvfbe