Model Calculation Of Neutron Kerma Coefficients For N + 56Fe Nuclear Reaction Below 20 MeV

Kerma coe?cients are important in many ?elds, such as determining the radia-tion damage in nuclear engineering, and the thermal conduction, and determining thedose delivery in therapy beams. iron is the main nuclear structural material, the datais of great signi?cance to the development of nuclear energy and nuclear engineeringconstruction. Such as accelerator driven clean power system (ADS) designs, ?ssiondesigns, fusion designs, neutron reactor designs and so on. Elemental iron consists offour isotopes, 54Fe (5.845% abundant), 56Fe (91.754% abundant), 57Fe (2.119% abun-dant), 58Fe (0.282% abundant). So each isotopes must be evaluated in order to obtainthe accurate kerma coe?cients of iron. However, the experimental data of four iso-topes (consist of neutron kerma coe?cients and others that have signi?cant in?uenceon neutron kerma coe?cients, such as elastic cross sections, elastic-scattering angu-lar distributions, inelastic cross sections, inelastic- scattering angular distributions,neutron double-di?erential cross sections and charged-particle double-di?erential crosssections) are very scarce, especially the incident neutron energy below 20 MeV. So atthis energy rang, it is signi?cantly referential value to accurately calculate the neutronkerma coe?cients using theory model for n + 56Fe reaction.Despite the neutron kerma coe?cients of Fe is very important, the experimentaldata are absent, and the uncertainties of experimental data are relative big, especiallythe incident neutron energy below 20 MeV. As mentioned by P. M. DeLuca et al, thegas contribution changes the energy deposition spectrum for Fe and must be taken intoaccount in determining the kerma coe?cients. There is a general tendency that theuncertainties increase with increasing neutron energy for Iron element above 15 MeVincident neutron energy. sometimes, the uncertainty is up to 90.9%. Therefore, caremust be taken when the data are applied above 15 MeV, as mentioned by R. S. Caswell.The evaluated kerma coe?cients below 20 MeV were usually derived from ENDF/B-VIformat libraries using the data processing codes. These codes take advantage of the facts that many evaluation libraries give explicit energy distributions for the emittedneutrons and photons. The limitation using data processing codes on the accuracyof neutron kerma calculation is determined by the availability and accuracy of theevaluation libraries. Furthermore, the kerma coe?cients of Iron element were onlyevaluated by M. B. Chadwick in 1999. These kerma coe?cients below 14.5 MeVwere obtained from existing ENDF/B-VI evaluated library using NJOY code, and thevalues in 14.5-20 MeV region were linearly interpolated, However Below 20 MeV, theENDF/B-VI information on charged-particle emission is incomplete.In this work, the reaction channels of n + 56Fe reaction are analyzed, on the basisof the Uni?ed Hauser-Feshbach and Excition Model, the energy formulas of all kindsof emitted particles in diversi?ed channels are given, and the energy balance is heldstrictly simultaneously. On the basis of this, the elastic scattering angle distributionsand cross section, total cross section, cross sections of (n,α) and (n, p) are calculatedused UNF(2009) code, these results are agree well with the experimental datas. So theoptical potential parameters of neutron, proton and charged particle are obtained. Anduseing these optical potential parameters, the double-di?erential cross sections of n, pandαparticle for n + 56Fe reaction below 20MeV are calculated. The calculations areagree well with the experimental data, so the total kerma coe?cient of n + 56Fe below20MeV is obtained naturally using the new formula of kerma coe?cient, which consistsmore parameter information. Below 14.5 MeV, the result of this work is agree withthe experimental data and the result of M. B. Chadwick. Although above 14.5 MeV,the result of this work is lower than the result of M. B. Chadwick and the measureddata. But, the more detailed information of neutron, proton and charged particlesare given in this work, and these information are agree well with the experimentaldata. Furthermore the formula of kerma coe?cient used in this work contains moredetailed, comprehensive information. So the result of total kerma coe?cients for n +56Fe nuclear reaction is reasonable to some extent, and these parameters can providesome reference to nuclear technology and nuclear engineering.