Neutron kerma factors for H, C, N, O and tissue in the energy range of 20-70 MeV

Calculated neutron kerma factors for H, C, N, O and tissue in the energy range of 20 to 70 MeV are presented. The available experimental data on charged-particle production from neutron interactions with C, N and O nuclei at energies >= 20 MeV are very limited, and thus the results presented here are based almost entirely on theoretical cross-section data. The method of calculation is briefly discussed and the results presented as kerma per unit fluence given as a function of energy for H, C, N, O and tissues. The results are discussed and compared to those of other workers. (U.K.)