Projectile Like Fragments from 129Xe + natCu reactions at E/A = 30, 40, 50 MeV

Abstract

There has been a great deal of experimental and theoretical interest in the modes of dissassembly of highly excited nuclear matter. However, the mechanisms by which these hot nuclei are formed is also important to the study of the energy dependence of the influence of the nuclear mean field. One method to form an excited system is via a damped reaction. First observed at energies just above the Coulomb barrier, damped reactions were thought to occur only at low energies. The persistance of the damped reaction mechanism into the intermediate energy regime, between 20 and 100 MeV per nucleon, has recently been seen experimentally[1, 2]. But how high in energy do damped reactions occur? In order to measure an excitation function for damped reactions, an experiment was performed at the National Superconducting Cyclotron Laboratory (NSCL) on the campus of Michigan State University (MSU). The experiment consisted of a 129Xe beam at energies of 30, 40, 50, and 60 MeV per nucleon incident on targets of nat Cu and nat Sc. Reaction products where detecting using the MSU 4πdetector system[3] augmented by the Maryland Forward Array[4] (MFA), a detector that covers between 1.4° and 2.9° from the beam in the laboratory.