Beam Dynamics Issues in the Post Accelerator for the Rare Isotope Ion Beams from ISOL System in RISP

The accelerator for RISP, which is the superconducting technology based heavy ion linear accelerator construction project, is composed mainly of the driver linac for stable ion beam from an ECR ion source and post linac for unstable ion from an ISOL system. The post accelerator can accelerate the unstable ion beams up to 16.5 MeV/u for 132 Sn and 16.0 MeV/u for 58 Ni, which has the ratio of mass to charge, A/q, of 8.3. The unstable ion beam such as 132 Sn from an ISOL system has the large initial transverse and longitudinal emittances. Hence acceptance and envelope of the post accelerator should be optimized for stable operation. The beam was transported by the post-to-driver transport (P2DT) line which consists of a charge stripper, two charge selection sections and a telescope section with the bunching cavities. In this presentation, we will show the criteria for the design of the post accelerator and result of beam tracking simulation from the low energy transport line to the end of post linac. The initial coordinates of the particles were acquired by the tracking simulation from the low energy beam transport (LEBT) line to the medium energy beam transport (MEBT) line.