Intranuclear cascade model for 50-MeV-region (p, p ′ x) reactions over a wide target mass range

In our previous study, the applicable range of the intranuclear cascade model was successfully extended to lower incident energy (p, p′x) reactions by introducing trajectory deflections and low-energy-loss process due to collective excitations. However, the model's validity was confirmed only for a ⁵⁶Fe target. In the present work we widen the applicable range of masses of the target nucleus. First, we derive an expression for the response function, which gives the probability of collective excitation strengths, to fit the distorted-wave Born approximation results as a function of the target mass number and the beam energy. Second, the barrier transmission coefficient was investigated. An expression with a modified Gamow penetration factor was chosen from four phenomenological forms of one-dimensional barrier transmission coefficients. Calculations with the proposed model followed by a generalized evaporation model were carried out for double-differential cross sections of (p, p′x) reactions at 30-60 MeV. Although the response function and the transmission coefficient were only parameterized approximately, the proposed model showed good agreements with experimental observations for a variety of nuclear targets from ¹²C to ²⁰⁹Bi.