Inclusive (p,p') reactions on nuclei in the mass range 115 to 181 at incident energies from 120 to 200 MeV

Double differential cross sections have been measured for inclusive ({ital p},{ital p}{sup {prime}}) reactions on {sup 115}In, {sup 167}Er, {sup 173}Yb, and {sup 181}Ta at incident proton energies of 120, 150, 175, and 200 MeV and for {sup 141}Pr at 120 and 200 MeV. These targets were chosen to investigate a possible mass dependence of the effective interaction strength when comparisons are made with multistep direct calculations based on the Feshbach, Kerman, and Koonin theory. The inclusion of two-nucleon emission is also investigated. The multiparticle emission contributes significantly at low emission energies and forward angles, but it is shown that the energy dependence of the strength of the effective interaction must also be taken into account to explain the discrepancy in this region. {copyright} {ital 1996 The American Physical Society.}