  The empirical calculations of the prompt neutrons average number for
photofission of the 232Th, 233U, 234U, 235U, 236U, 238U, 237Np, 239Pu and 241Am
actinides has been done as a function of photon energy, mass and charge of the
nuclei, which can be used to evaluate the average number for photo-fission of
nuclides for which no or scarce data are available.
