ICRU Report 63, Nuclear Data for Neutron and Proton Radiotherapy and for Radiation Protection


This Report represents a departure for the ICRU in that it includes a compact disc carrying an extensive compilation of data. Included in this publication is a comprehensive tabulation of nuclear data especially relevant for medical, industrial, research, and protection applications. Extensive microscopic cross-sections for neutron and proton interaction with elements important to dosimetry, radiation transport, and industrial applications are provided. For each application, the granularity of the data tabulations reflects the anticipated needs.

Hence, the data for tissue elements, H,C,N, and O, are very complete and with a fine energy grid. In contrast, the data for iron and lead are designed for shielding calculations and radiation transport. Elastic and inelastic and total cross section data are extensive, but secondary charged particle producing reaction data are sparser. A coarser energy grid is used. Considerable data are supplied in the Report, but the accompanying CD-ROM contains very extensive compilations in a very easily understood format, (ENDF-6). Neutron-induced nuclear reaction cross sections and kerma coefficients are presented up to 150 MeV, and proton-induced cross sections are presented up to 250 MeV. The nuclear cross sections are evaluated using a combination of measured data and nuclear model calculations. The Report reviews measurements from which cross sections and kerma coefficients have been determined, but since there are only a limited number of experimental data sets for biologically-important target elements, theoretical predictions are needed to supplement these data. For this purpose, use is made of the GNASH nuclear model code, which applies theories for compound nucleus, pre-equilibrium, and direct reaction mechanisms. Optical model calculations served to determine total, total nonelastic and elastic scattering cross sections. Numerous benchmarks are presented that compare the model predictions with measured data to validate the calculations of energy- and angle-dependent emission spectra, as well as total, nonelastic, and elastic scattering cross sections. For hydrogen, an evaluation is described that uses both R-matrix and phase-shift scattering theories to represent neutron-proton reaction data. Kerma coefficients are derived from the evaluated neutron-induced cross sections and presented for individual elements as well as for ICRU muscle, A-150 tissue-equivalent plastic, and other compounds which are important for treatment planning and dosimetry.