Beam loss simulations for space charge mitigation in J-PARC MR

The main ring synchrotron (MR) of the Japan Proton Accelerator Research Complex (J-PARC) provides high power proton beams to neutrino and hadron experiments. Since we are planning to increase the beam intensity from current $2.3 \times 10^{14}~$protons per pulse (ppp) to $3.3 \times 10^{14}~$ppp, we need to reduce the beam loss. In the J-PARC MR, the space charge is one of the main causes of beam loss. As a first step, we developed a new beam optics suppressing the space-charge-induced resonance which is the primary cause of the beam loss. In this paper, we report details of the beam loss mechanism in J-PARC MR by comparing the tune scan results of the present and new beam optics.