Incident energy dependence of preequilibrium (p, p′) spectra

Proton energy spectra from (p, xp) reactions on⁹⁸Mo and¹⁰⁶Pd have been measured at incident energies of 12, 14, and 16 MeV to investigate the incident energy dependence of preequilibrium (p, p′) process. The (p, xp) energy spectrum for⁶⁰Ni has also been measured at an incident energy of 18 MeV to confirm the mass number dependence. These spectra were compared with a calculation based on the exciton model in which the square of the average effective matrix element |M|² was assumed to be KA^-3E^-1 and isospin conservation was taken into account. The calculated spectra using a constant K-value (430 MeV³) were in good agreement with all the measured ones. The role of isospin conservation in preequilibrium process was discussed through the present analyses.