Lattice and collimation system for J-PARC

Kinsho, Michikazu  

JAERI and KEK have been working on the J-PARC project for a high intensity proton accelerator. The accelerator complex consists of a 400MeV linac, a 3GeV rapid cycle synchrotron, and a 50GeV synchrotron ring. The major requirements for the accelerator are summarized as follows, (1) The accelerator should provide the 1MW beam with a repetition rate of 25 Hz and a pulse length less than 1 us to the full use of pulsed spallation neutrons. (2) It should provide the several ten GeV beams with a beam power of 0.75MW for nuclear and particle physics experiments. As for the design of such a high intensity proton accelerator, from the experience of the past accelerator operation, the average beam loss should be kept at an order of 1W/m with a view to hands-on maintenance. Accordingly, there are several kinds of beam collimator in each accelerator and beam transport lines to minimize and localize the beam loss. We reported mainly the design concept and simulation results of the beam loss for each section.