Abstract
The Griffin or exciton model for preequilibrium nuclear reactions has been extended so that particle unbound states in the equilibrating system are distinguished from bound states. This permits the preequilibrium cross section to be divided into components due to multistep direct and multistep compound processes for calculation of emitted particle angular distributions. Preequilibrium models traditionally assume that all states of a given particle-hole number are equally likely whereas present work indicates that unbound states are preferentially populated. Nevertheless, the emission energy spectra calculated are not significantly changed from earlier versions of the model.