Bunch compression in a ring for future RIKEN projects

Possible ion beam parameters are investigated for bunch compression in the TARN II storage ring which is under consideration for applications at RIKEN. A fast rotation scheme is carried out to generate a high-current beam within the ring after accumulating and cooling a low-current ion beam. Consistent with achievable magnetic rigidity and space-charge tune shift, possible beam parameters during the beam stacking in the ring are estimated analytically. Beam properties during the bunch compression are studied with coupled envelope equations that take into account space-charge and dispersive forces acting on the beam. More self-consistent particle-in-cell simulations are also carried out, and the results are compared with the envelope calculations.