Acceleration Simulation of PEFP RCS for a 1-GeV Extraction

The conceptual design of an RCS (rapid cycling synchrotron) is under progress as an extension plan of the PEFP (proton engineering frontier project). The 100-MeV linac of the project becomes the injector of the synchrotron whose main purpose is a spallation neutron source. In the initial stage, the beam power is 60 kW and the injection and extraction energies are 100 MeV and 1 GeV, respectively. They become 200 MeV and 2 GeV for the beam power of 500 kW after 3-step upgrade. For the research in the basic science and medical area, the machine also includes a slow extraction option for the energy range up to 450-MeV. This work focuses on the acceleration simulation of the RCS in 1-GeV operation. The ORBIT code was used for the beam dynamics simulation. We found that the capture rate is larger than 99.9 % if the initial RF voltage is 18.7 kV and the maximum voltage is 75 kV