Improving precision and data access in photon evaporation for NRF simulations

Omer, M.   

In the current implementation of reading photon evaporation, gamma-transition intensities and internal conversion coefficients (ICC) are processed using float precision. This leads to cumulative rounding errors during transition sampling, resulting in false-positive or false-negative transitions in complex nuclei. Furthermore, there is no explicit application programming interface (API) to access raw intensities directly from the data files. We suggest that the coming Geant4 releases would provide a direct interface to retrieve the raw gamma intensities as they appear in the photon evaporation data files, bypassing the current probability wrappers for those who need them. This should be implemented in G4LevelManager, G4NucLevel, and G4NuclearLevelData classes as well.