Accelerator design for 1.3-MW beam power operation of the J-PARC Main Ring

Abstract

The J-PARC Main Ring (MR) has supplied the high-intensity proton beam for the T2K long-baseline neutrino experiment since 2010. The present beam power is 510 kW and the total number of protons on the target reaches 3.64 × 1021. To observe CP violation in the lepton sector with high accuracy, more protons need to be delivered to the T2K target. The project to upgrade the beam power to 1.3 MW started as a mid-term plan of the MR. In parallel to preparing a full technical design report, the technical designs of hardware upgrades using new technologies and all accelerator components that are necessary to deliver the 1.3-MW beam power are summarized and consolidated in this short paper. Further, this paper includes beam dynamics studies and simulation results for handling 3.3 × 1014 protons per pulse (ppp) without significant beam loss in the ring and transport lines. The Hyper-Kamiokande (HK) project has recently been approved, and construction has started; the MR upgrade and HK project will work together efficiently to study the CP violation.

First Result of the High Repetition Operation in J-PARC MR

“…The MR set a world record for the beam intensity of 2.66 × 10 14 protons per pulse (ppp), corresponding to the beam power of 515 kW [6]. To realize higher statistic physical experiments, we launched an upgrade plan aiming at 1.3 MW FX operation [7]. This upgrade plan consists of higher repetition, reinforcement of the RF system, and beam loss reduction/localization.…”