Production of neutron-rich isotopes by cold fragmentation in the reaction "1"9"7Au + Be at 950 A MeV

Abstract

The production cross sections and longitudinal-momentum distributions of very neutron-rich isotopes have been investigated in the fragmentation of a 950 A MeV "1"7"9Au beam in a beryllium target. Seven new isotopes ("1"9"3Re, "1"9"4Re, "1"9"1W, "1"9"2W, "1"8"9Ta, "1"8"7Hf and "1"8"8Hf) and the five-proton-removal channel were observed for the first time. The reaction mechanism leading to the formation of these very neutron-rich isotopes is explained in terms of the cold-fragmentation process. An analytical model describing this reaction mechanism is presented. (orig.)Available from TIB Hannover: RO 801(99-35) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman