Spectroscopic intercomparison at the German neutron therapy centers.
An intercomparison of neutron dosimetry at the German neutron therapy centers at Hamburg, Heidelberg and Essen has been performed in 1979 and 1980. This intercomparison was undertaken to compare the experimental procedures and techniques for fast neutron dosimetry applied by each group. Because of the energy dependence of the dosimeters, spectroscopic investigations were performed at positions in the phantom identical to those applied during the dosimetric measurements. A description of the experimental procedures and environments is given. The measured neutron spectra are presented and discussed with respect to the changes at different positions in the phantom. Individual kerma-ratios are calculated from the neutron and photon energy distributions. The comparison of these kerma-ratios gives considerable differences in values that are used with neutron-insensitive ionization chambers. We recommend that individual generated kerma-ratios should be applied for ionization chamber dosimetry.
D008027:Light; D009502:Neutrons; D011874:Radiometry; D011882:Radiotherapy, High-Energy