Kerma factors for neutrons with energies up to 60 MeV

As a result of a collaborative programme on the dosimetry of neutrons with energies between 15 and 60 MeV, a revision of calculated kerma factors has been made, and these have been compared with recently published experimental measurements on neutron-induced particles in carbon, nitrogen and oxygen by Subramanian et al (1980). Kerma factors are tabulated for elemental H, C, N and O, ICRU tissue, A-150 plastic, TE gas and water. It is concluded that although there is now reasonably good agreement with experiment for total kerma, analysis of the partial kermas showed serious differences with experiment for light-particle production which would make it inappropriate to apply the present theoretical cross-section data to, for example, calculations of microdosimetry distributions. It appears that the cross-sections for alpha-producing reactions are unduly high at the expense of the lighter particles. (U.K.)