Modification of photo-nuclear cascade evaporation code PICA95 at energies below 150 MeV

In our previous works, it was found that the photonuclear reaction yields evaluated by the combination of PICA95 and EGS4 tended to overestimate the experimental ones. In order to solve the discrepancy, we modified the PICA95 following four points. The calculation method for the cross section of quasi-deuteron distintegration (QDD) was changed without using the normalized parameter. The giant resonance was taken into account by using its cross section fitted by Lorentz curve. The parameterized in-medium nucleon–nucleon scattering cross section was substituted for that in free space. The mass formula and level density parameter used in the calculation process of evaporation was updated. The yields calculated by the modified PICA95 agreed better with experimental values than with the values obtained from the original PICA95 code.