Energy deposition and GDR emission in the reaction Bi-209(alpha,alpha ') at 240 MeV

Neutron fold distributions measured for the reaction Bi-209(alpha,alpha') a t 240 MeV have been analyzed with the help of Statistical Model calculation s to determine the distribution of excitation energy, E-x, in the primary t arget fragments as a function of the projectile energy loss, EL. The recons tructed 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 lea ds to the selection of a significant higher average excitation energy. Thos e results are extrapolated to explore the effects of including the excitati on energy distributions in the analysis of previous GDR measurements in Pb- 208. Corrections of the derived GDR parameters due to the partial transfer of excitation energy are suggested. (C) 1999 Elsevier Science B.V. All righ ts reserved.