RIKEN, Wako, Saitama
In 2008, the RIKEN RI-Beam Factory (RIBF) succeeded in providing heavy ion beams of 48Ca and 238U with 170 particle-nano-ampere and 0.4 particle-nano-ampere, respectively, at an energy of 345 MeV/u. The transmission efficiency through the accelerator chain has been signifcantly improved owing to the continuous efforts paid since the first beam in 2006. From the operational point of view, however, the intensity of the uranium beam should be much increased. We have, therefore, constructed a superconducting ECR ion source which is capable of the microwave power of 28 GHz. In order to reduce the space-charge effects, the ion source was installed on the high-voltage terminal of the Cockcroft-Walton pre-injector, where the beam from the source will be directly injected into the heavy-ion linac by skipping the RFQ pre-injector. The test of the ion source on the platform has started recently with an existing microwave source of 18 GHz. This pre-injector will be available in October 2009. We will show further upgrade plan of constructing an alternative injector for the RIBF, consisting of the superconducting ECR ion source, an RFQ, and three DTL tanks. An RFQ linac, which has been originally developed for the ion-implantation application will be reused for the new injector. Modification of the RFQ as well as the design study of the DTL are under progress. The new injector, which will be ready in FY2010, aims at independent operation of the RIBF experiments and super-heavy element synthesis.
