Proton Radioactivity Studies At ATLAS

摘要

Several searches for new proton emitters were performed recently at ATLAS using the Argonne Fragment Mass Analyzer equipped with a Double-Sided Si Strip Detector. Proton emitting states were observed in odd-odd spherical nuclei ~(164)Ir and ~(170)Au. ~(164)Ir is the fourth Ir proton emitter. A proton line was associated with the highly deformed odd-odd nucleus ~(130)Eu. The proton emitter ~(135)Tb was also observed. It is the first proton emitting Tb isotope. The estimated cross section for producing ~(135)Tb is about 2 nb. The properties of the proton emitters deduced from this work helped to understand the role of core vibrations and neutrons in proton decay. In view of the present results the full delineation of the proton drip-line between Z=50 and Z=83 is feasible. In order to cope with small cross sections and short half lives expected for even more exotic proton emitters several modifications of the FMA implantation station were implemented. Measurements were also performed at the target position using a catcher to search for proton emitters with half lives down to 10 ns.