A consistent set of neutron kerma coefficients from thermal to 150 MeV for biologically important materials

Abstract

Neutron cross sections for nonelastic and elastic reactions on a range of elements have been evaluated for incident energies up to 150 MeV. These cross sections agree well with experimental cross section data for charged-particle production as well as neutron and photon production. Therefore they can be used to determine kerma coefficients for calculations of energy deposition by neutrons in matter. Methods used to evaluate the neutron cross sections above 20 MeV, using nuclear model calculations and experimental data, are described. Below 20 MeV, the evaluated cross sections from the ENDF/B-VI library are adopted. Comparisons are shown between the evaluated charged-particle production cross sections and measured data. Kerma coefficients are derived from the neutron cross sections, for major isotopes of H, C, N, O, Al, Si, P, Ca, Fe, Cu, W, Pb, and for ICRU-muscle, A-150 tissue-equivalent plastic, and other compounds important for treatment planning and dosimetry. Numerous comparisons are made between our kerma coefficients and experimental kerma coefficient data, to validate our results, and agreement is found to be good. An important quantity in neutron dosimetry is the kerma coefficient ratio of ICRU-muscle to A-150 plastic. When this ratio is calculated from our kerma coefficient data, and averaged over the neutron energy spectra for higher-energy clinical therapy beams [three p (68) + Be beams, and a d (48.5) + Be beam], a value of 0.94 +/- 0.03 is obtained. Kerma ratios for water to A-150 plastic, and carbon to oxygen, are also compared with measurements where available.

Statistical theory of light nucleus reactions with 1p-shell light nuclei

“…Similarly, the calculated total DDCS of outgoing neutrons at other angles also agree well with the experimental data. It is worth mentioning that the contributions of two predicted energy levels 9.0(5/2 + ) and 10.0(5/2 + ) of 9 Be are added to obtain the DDCS of the total outgoing neutron as shown the solid lines in Figs. 3 and 4 [5] and Figs.…”

“…The model calculations of the DDCS of the total outgoing neutron had been performed for reactions such as 12 C(n, xn), 9 Be(n, xn), 16 O(n, xn) and 9 Be(p,xn). The calculated results for the different outgoing angles at different incident energies (taking E n = 18 MeV example in this paper) agree fairly well with the measurements as shown in Figs.…”

Neutron, proton, and photonuclear cross-sections for radiation therapy and radiation protection

“…Comparisons of kerma coefficient data for other elements and A150 plastic, and the kerma ratios for carbon to oxygen and ICRU-muscle to A-150 plastic, are given in Refs. [5,7].…”

“…A comprehensive description of our calculated kerma coefficients up to 150 MeV for elements and mixtures/compounds important in dosimetry is given in Ref. [7]. In parallel to work on the evaluation of nuclear cross sections, Monte Carlo radiation transport codes are under development to utilize these data.…”

Measurement and model analysis of(n,xα)cross sections for Cr, Fe,59Co, andKunieda1, Haight2, Kawano3 et al. 2012Phys. Rev. CSelf Cite25030View full textAdd to dashboardCite

“…In addition to the aforementioned applications in gas production and material damage, other applications include neutron heating (kerma) for radiation therapy [16,17] and single-event upsets [18,19].…”