Inclusive and exclusive preequilibrium spectra in a model of independently interacting excitons

Starting from a previous ansatz ofindependently interacting excitons the more refined model INCLUSIVE INDEX is developed yieldinginclusive preequilibrium proton and neutron spectra. It is shown that three stages are sufficient to describe single- and multi-nucleon emission to all orders of practical importance. By use of recurrence relations the loss of particles and energy due to emission from previous stages is fully accounted for. In order to predict the population of specific residual nuclei the precompound process is reformulated in terms ofexclusive emission spectra. This intricate statistical problem is solved in the EXCLUSIVE INDEX model by algorithms representing the average probability for a specified number of particles not to be emitted but to reach the next stage of nuclear relaxation. Differential excitation probabilities can be calculated for those six nuclei which are populated by the emission of none, one, or two preequilibrium nucleons in two stages via alltogether 15 principal paths. Typical features of the INCLUSIVE and EXCLUSIVE INDEX model are discussed. The strength of one- and two-nucleon emission is compared with HYBRID model predictions.