VALIDATION OF SPALLATION MODELS FOR p plus Al REACTIONS AT 180 MeV INCIDENT PROTON BEAM ENERGY

Various observables measured at low beam energy of 180 MeV for proton induced reactions on (27) l targets have been compared with theoretical predictions of different spallation models. These models assume that the reactions proceed in two stages: the intranuclear cascade of nucleon-nucleon collisions followed by the de-excitation of equilibrated, excited remnants of the cascade. The calculations of the intranuclear cascade were performed by means of the INCL4.6 code, whereas the second stage of the reactions was realized using four different models: ABLA07, GEMINI++, GEM2, and SMM. It was found that the main properties of the experimental isobaric total production cross sections are reasonably well reproduced by all these spallation models. The shape of the energy averaged angular distributions of ejectiles with A = 7, 12, 16, 22, 24, and 25 was also well described by the models listed above, however the absolute magnitude of A = 7 and A = 25 data is strongly underestimated and overestimated, respectively. The theoretical energy spectra for A = 7, A = 16, and A = 22 are very similar for all the models and reproduce well the data for heavier ejectiles, whereas the A = 7 data deviate from the model cross sections for energies smaller than approximate to 1 0 MeV what may indicate the presence of a reaction mechanism not included in the spallation models. The following ranking of the four used models - all of them being coupled to the very same INCL4.6 INC model - was determined using the statistical H-test in a quantitative analysis: (1) GEMINI++, (2) SMM, (3) ABLA07, and (4) GEM2.