Anomalous gamma-ray multiplicity distributions-evidence for pre-equilibrium neutron emission

Abstract

Multiplicity distributions and 〈 E γ 〉 have been measured for the 124 Sn( 40 Ar, x n) 164−x Er reaction at E(Ar) = 161, 182, 189, 209, and 236 MeV. The data at E(Ar) = 236 MeV indicate that pre-equilibrium neutrons are emitted. These data, together with other reactions leading to Er final systems, are discussed in terms of pre-equilibrium mechanisms.