Beam Spreading of the 100-MeV Proton Beam by Using the Double-Scattering Method at the PEFP Beamlines of the User Facility

摘要

The Proton Engineering Frontier Project (PEFP) will construct a beam utilization facility based on a user demand survey and on the operation experience of the 45-MeV proton beam test irradiation facility. Since most of the users have demanded a broad and uniform proton beam for their research, we investigated the beam spreading method, which is suitable for the 100-MeV beamline, by using the double-scattering method. We derived the optimum parameters of the double-scatterer by using a systematic method. Then, we applied that method to the target room for the BL 102 and 104 beamline. Considering the limited space of the target room and the energy loss of the 100-MeV proton beam, we found that we could obtain a uniform beam field of 20 cm. The distance between the first scatterer and the iso-center plane is 300 cm, the distance between the second scatterer and the iso-center plane is fixed as 240 cm andthe material of the first and the second scatterers are tungsten and aluminums alloy, respectively. We have designed preliminary double scatters for the 100-MeV PEFP beamline by using the optimum parameters andthat design of the double scatterers was verified by Monte Carlo Method.