NEW DESIGN OF J-PARC MAIN RING INJECTION SYSTEM FOR HIGH BEAM POWER OPERATION

The present J-PARC main ring (MR) injection system has worked for 6 years since 2008, and the performance has been improved a lot by correcting the original design faults. But there are still problems in the existing injection system that affects the daily operation. In order to realize the MR beam power to the design limit, a high performance injection system is crucial. The remaining problems may have severe effects on high intensity beam, and become a big block to the realization of high beam power operation. Thus, upgrade the present injection system to satisfy the demands of high beam power operation is extremely important. The upgrade will redesign injection septa to obtain high performance, which will reduce the leakage field greatly. The kicker rise time will be reduced greatly by optimizing the configuration and using speed-up circuit. A compensation kicker magnet is being studied for reflection tail field cancelation. Careful 3D electromagnetic field simulations and 3D particle tracking are performed to ensure the accuracy of magnets design.