KEK, Ibaraki
From April 2010 the routine operation of the J-PARC Main Ring for the Neutrino experiments has begun, providing the moderate beam power at the maximum energy of 30GeV. The beam intensity delivered to Main Ring from the booster (rapid cycling synchrotron, J-PARC RCS) is about 1.25·1013 protons per bunch, which corresponds to the beam power of 300kW at the energy of 3GeV. The maximum expected beam power from Main Ring for the ‘phass-1’ stage is about 145kW (8 bunches operation, the repetition time is 3.3 sec). To optimize the machine performance, providing minimum particle losses during the injection and acceleration processes, the computational model of the J-PARC Main Ring has been established. In frame of this report the comparison between predictions, based on the corresponding simulations, and measured beam losses for different ‘bare’ tunes is performed. The effects of the linear coupling correction at the moderate beam power are analyzed for the J-PARC Main Ring operation. The predicted and obtained budget of the lost beam for the machine operation with the moderate beam power is presented. The basic scenario for the high beam power operation will be discussed shortly.
