Energy deposition in reactions at

The reaction Bi-209(alpha,alpha') has been studied E-Beam = 240 MeV, exploring the possibility of producing hot nuclei with low-angular momentum, in the mass region A similar to 200, suitable for studies of the level-density parameter. The possibility of using the energy of the inelastically scattered alpha particles to determine the excitation energy deposited in the target nucleus has been checked by measuring evaporated charged particles, neutrons, fission fragments and gamma-rays. Comparison of the (alpha, alpha') data with results from the fusion reaction B-11 + Pt-198 --> Bi-209 and statistical model calculations seems to indicate that, in the case of inelastic cr scattering, not all the energy dissipated in the collision is normally deposited as thermal excitation in the target nucleus. From evaporated proton spectra there is evidence for a strong pre-equilibrium component even at the most backward angles.