STUDIES at the RIKEN RI BEAM FACTORY

Abstract

The RIKEN RI Beam Factory (RIBF) project has reached a milestone in Dec. 2006 by extracting the first beam. Its basic part, accelerators and a superconducting RI beam separator called BigRIPS are now in operation. The first experimental result, production of a new neutron-rich isotope 125Pd, was obtained in May 2007 with 345 MeV/nucleon 238U beams. The RIBF project was launched about ten years ago, encouraged by success of nuclear physics and nuclear astrophysics studies using fast RI beams produced by the accelerator facility which has been running since 1986. At RIBF, radioactive isotope (RI) beams are produced via the projectile fragmentation of heavy ions or in-flight fission of uranium ions. Most of the expected path of the r-process nucleosynthesis can be reached with the intensity higher than one particle per day. In view of its outstanding performance on the variety and intensity of RI beams, the RIBF is one of the new-generation facilities competitive to those planned in the United States (FRIB) and Europe (FAIR at GSI), and is their first realization.