Production and separation of neutron-rich rare isotopes around and below the Fermi energy

Abstract

The production of n-rich rare isotopes around and below the Fermi energy is investigated using beams from the K500 Superconducting Cyclotron and the MARS recoil separator at the Cyclotron Institute of Texas A&M University. The experimental results from the reactions of 25 MeV/nucleon 86Kr + 64Ni and 21 MeV/nucleon 124Sn + 124Sn are presented and compared with simulations. The calculations involve a deep inelastic transfer (DIT) code for the primary interaction stage followed by the code GEMINI for the de-excitation stage. The results are also compared with the EPAX parametrization. The data on the 25 MeV/nucleon 86Kr + 64Ni reaction show that both proton-removal and several-neutron pick-up isotopes are produced. An enhancement is observed in the production of n-rich isotopes close to the projectile relative to the predictions of DIT/GEMINI and the expectations of EPAX. The data of 21 MeV/nucleon 124Sn + 124Sn for fragments away from the projectile ( Z=30–20) show also production of very n-rich nuclides, despite the less peripheral character of these collisions. In general, the large cross sections of n-rich nuclides from these reactions around the Fermi energy indicate that they may be exploited to produce beams of very n-rich rare isotopes. The application of such reactions in current plans of rare beam production at Texas A&M using a superconducting solenoid line will be described.