The Study Of Neutron Kerma Coefficients For N+¹²C(¹⁶O) Nuclear Reaction Below 30 MeV

Kerma (kinetic energy released in materials) coefficients are important in many fields, such as determining the radiation scathing and shielding in nucleus engineering, predicting and analyzing the thermomechanical performance, and determining the dose delivery in therapy beams. And the ¹²C and ¹⁶O kerma coefficients are the most important and useful.According the new model of neutron induced light nucleus reactions, this thesis determine a new kerma coefficients formula which can calculate kerma coefficients for all kinds of emitted particles in diversified channels. of the charged particle or recoil nuclear of type j in nucleus reactions. In the laboratory system,εijk ( En) andσijk ( En)are the average energy (expressed in MeV) and production cross section (expressed in barns), which are all the function of the incident neutron energy E n. Here, i denotes the type of reaction channels and k signs the excitation energy level of residual nucleus which can emit the secondary particle, or proceed via two-body separation, or carry out gamma decay.It is the first time to present such particular and comprehensive information for kerma coefficients. On the basis of this new model, LUNF code is modified to calculate part and total kerma coefficient for n+¹²C and n+¹⁶O reactions from the threshold energy to 30 MeV. We have calculated the kerma coefficients of alpha, protons, deuterons, tritons, He3, Li6, elastic recoil and total at n+¹²C and n+¹⁶O reactions. The results agree fairly well with the experimental data and evaluations. We analyze the channels carefully and gain the average energiesεijkof all kinds of the emitted particles in the laboratory frame. At the same time, we obtained new optical potential parameters for ¹²C and ¹⁶O respectively.However, the new model of neutron induced light nucleus reactions can obtain the cross section of total and elastic scattering in a smooth curve only, but their experimental and evaluated cross sections have many structures at the low neutron energy region. So, the elastic cross section and their 1st Legendre coefficient 11f mderived from CENDL-3.1 are used when we calculate the kerma coefficients of ¹²C, and the elastic cross section and their 1st Legendre coefficient 11f mderived from ENDF/B-VII6.3 are used when we calculate the kerma coefficients of ¹⁶O. And then the kerma coefficients of total and elastic recoil agree fairly well with the experimental data and evaluations at the low neutron energy region.Studying the kerma coefficients for n+¹²C and n+¹⁶O are an important development for the model of neutron induced light nucleus reactions. We hope this model can solve the problem that there have not the good theory models to calculate the light nucleus reactions at the low neutron energy region. At the same time, we hope that we can spread this way to solve other nuclides, materials, tissue substitutes and therapy beams. And then we can provide the usable data of kerma coefficients for nuclear engineering and nuclear medicine.