Pre-equilibrium emission of light composite particles in the framework of the exciton model

The exciton model for the pre-equilibrium emission of light composite particles proposed and applied to the (p, $\alpha$) reaction of Iwamoto-Harada is further investigated for the energy spectra of the (p,d), (p,t), and (p,${}_{}{}^3{}_{}{}^{}\mathrm{He}$) reactions with incident energy of several tens of MeV's. Calculated results could reproduce an overall feature of those spectra. The dominance of the pickup-type contribution which occurs in the course of the equilibration process was found to be common for all composite particles. The degree of fitting to the data is excellent for (p,t) reactions to the same extent as for (p, $\alpha$) reactions, and is somewhat less for the high energy part of energy spectra of (p,${}_{}{}^3{}_{}{}^{}\mathrm{He}$) and (p,d) reactions. The relative ratio of yields of high energy composite particles was also reproduced fairly well with our model. These facts suggest that the simple reaction mechanism assumed in our model accounts for characteristics of the pre-equilibrium emission of light composite particles.