Beam Current Limitations due to Single-Beam Collective Effects in the Ion Storage Ring of RIKEN RI Beam Factory Project

摘要

Single-beam collective effects limit the beam current when beams are served for colliding experiments in the presently designed ion ring. For the some hundreds MeV/u ion beam making the betatron tune shift -0.2, longitudinal instabilities occur with growth times of 0.02 s, and the transverse resistive wall instability with growth time of 1 s. The electron cooling with cooling time of 0.01 s at the full momentum spread 10~(-3) of the ion beams can damp the instabilities. Then, the luminosity is much less than 1×10~(27) cm~(-2)s~(-1) on the heavy ion side. A proposal about the lattice of the ring is made to improve the luminosity.