Production cross section measurements of radioactive isotopes by BigRIPS separator at RIKEN RI Beam Factory

We have measured the production rates and production cross sections for a variety of radioactive isotopes which were produced from Xe-124, Ca-48, and U-238 beams at an energy of 345 MeV/nucleon using the BigRIPS separator at the RIKEN Nishina Center RI Beam Factory (RIBF). Proton-rich isotopes with atomic numbers Z = 40-52 and neutron-rich isotopes with Z = 5-.16 were produced by projectile fragmentation of the Xe-124 and Ca-48 beam on Be targets, respectively. Neutron-rich isotopes with Z = 20-59 were produced by in-flight fission of the U-238 beam, in which both Be and Pb were used as production targets. The measured production rates and production cross sections were compared with those of the USE calculations, and overall fairly good agreement has been obtained. Furthermore, in the measurements with the Xe-124 beam, we have discovered four new isotopes on the proton-drip line, Ru-85,Ru-86 and Mo-81.82, and obtained the clear evidence that Sb-103 is particle unbound with an upper limit of 49 ns for the half-life. The measurements of projectile-fragment momentum distributions have been also performed with the Xe-124 beam, in which the low-momentum tails of the distributions have been measured for the first time at the energy of 345 MeV/nucleon. (C) 2013 Elsevier B.V. All rights reserved.