Synchrotron design issues of the Japanese Hadron Project

The accelerator complex of the Japanese Hadron Project (JHP) consists of 200MeV proton linear accelerator, 3GeV fast cycling booster synchrotron, and 50GeV main synchrotron. One of challenging issues of those synchrotrons is the injection, acceleration and extraction (both slow and fast mode) of high beam current with minimum beam loss. The average beam current of the booster synchrotron is 200μA and that of the main ring is 10μA, which are realized by 25Hz repetition of an acceleration cycle with 5x10 particles per pulse (ppp) and 0.3Hz of that with 2x10 ppp, respectively. Heavy beam loading has to be overcome in the longitudinal plane and space charge effects and other collective beam instabilities are cured in the transverse planes. The machines are expected to be built in the KEK campus.