High efficiency ISOL system to produce neutron deficient short-lived alkali RIBs on GANIL/SPIRAL 1 facility

摘要

The SPIRAL1 (Systeme de Production d'lons Radioactifs Acceleres en Ligne) facility at GANIL (Grand Acceierateur National d'lons Lourds) is developing new techniques to access nuclei in the neutron-deficient isotope region far from the stability-valley, with Z ranging from 30 to 60. The availability of different primary beams, ranging from carbon to uranium with energies up to 95 MeV/A, gives an opportunity to produce a large variety of radioactive ion beams. The production of neutron-deficient short-lived alkalis by fusion-evaporation reactions is the focus of this work. A simple and compact target ion source system (TISS) is designed to produce isotopes of ~(74)Rb (τ_(1/2) = 64.8 ms) and ~(114)Cs (τ_(1/2) = 570 ms). The efficiencies of the different processes involved in the production are evaluated. Radioactive recoils are produced through the interaction of heavy-ion beams, respectively ~(20)Ne beam and ~(58)Ni beam at an intensity of 10~(13) and 10~(12) pps, with a thin ~(58)Ni target. High atom-to-ion transformation (ATI) efficiency should be obtained above 70% and 90% for ~(74)Rb and ~(114)Cs nuclei respectively. The expected intensities of the RIBs are estimated to be around 10~4 pps at the exit of the TISS.