Partial Equilibrium Model for Nuclear Reactions

A new model for nuclear reactions is proposed in order to investigate the intermediate resonances'' detected experimentally in the intermediate energy region. The basic assumption is that only several nucleons of the target nucleus are excited at the compound system. Calculations are made in terms of the concept of the partial-equilibriumcompound-nucleus and the direct interaction. Numerical results for the level distances of the intermediate resonances'' agree with experiment. The number of excited nucleons in the compound system is about six and depends slightly on the excitation energy or the mass number of target nucleus (in this energy region). Further it is shown that outgoing channels couple with each other to form a gross channel corresponding to the intermediate level'' of the residual nucleus. The average distances between the gross channels are about 300 kev. (auth)