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

Proton energy spectra from (p, xp) reactions on 98Mo and 106Pd 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 for 60Ni 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 vertical strokeMvertical stroke2 was assumed to be KA-3 E-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. (orig.)