Energy deposition and GDR emission in the reaction 209Bi(α,α′) at 240 MeV

Abstract

Neutron fold distributions measured for the reaction 209Bi(α,α′) at 240 MeV have been analyzed with the help of Statistical Model calculations to determine the distribution of excitation energy, E x , in the primary target fragments as a function of the projectile energy loss, EL. The reconstructed distributions in excitation energy feature a plateau which extends from the kinematical limit E x = EL to very small excitations, indicating a variety of interactions of the beam particles with the target nucleus. The requirement of an additional coincidence with a light charged particle leads to the selection of a significant higher average excitation energy. Those results are extrapolated to explore the effects of including the excitation energy distributions in the analysis of previous GDR measurements in 208Pb. Corrections of the derived GDR parameters due to the partial transfer of excitation energy are suggested.