A new method for analyzing the collimation angle of a neutron Soller collimator is described. A Gaus- sian distribution formula is used to define the angular distribution function of the neutron source and the neutron...A new method for analyzing the collimation angle of a neutron Soller collimator is described. A Gaus- sian distribution formula is used to define the angular distribution function of the neutron source and the neutron transmission function of the Soller collimator. A relationship between the FWHM of the collimator rocking curve and the collimation angle is derived. Using this method, some rocking curve experiment results are analyzed. The results show that the new function can be a good theoretical model for fitting the experimental data, especially for the data of two collimators with different collimation angles.展开更多
A version of Geant4 has been developed to treat high-energy proton radiography. This article presents the results of calculations simulating the effects of nuclear elastic scattering for various test step wedges. Comp...A version of Geant4 has been developed to treat high-energy proton radiography. This article presents the results of calculations simulating the effects of nuclear elastic scattering for various test step wedges. Comparisons with experimental data are also presented. The traditional expressions of the transmission should be correct if the angle distribution of the scattering is Gaussian multiple Coulomb scattering. The mean free path（which depends on the collimator angle） and the radiation length are treated as empirical parameters, according to transmission as a function of thickness obtained by simulations. The results can be used in density reconstruction, which depends on the transmission expressions.展开更多
基金Supported by National Natural Science Foundation of China(11205248)
文摘A new method for analyzing the collimation angle of a neutron Soller collimator is described. A Gaus- sian distribution formula is used to define the angular distribution function of the neutron source and the neutron transmission function of the Soller collimator. A relationship between the FWHM of the collimator rocking curve and the collimation angle is derived. Using this method, some rocking curve experiment results are analyzed. The results show that the new function can be a good theoretical model for fitting the experimental data, especially for the data of two collimators with different collimation angles.
基金Supported by NSAF(11176001)Science and Technology Developing Foundation of China Academy of Engineering Physics(2012A0202006)
文摘A version of Geant4 has been developed to treat high-energy proton radiography. This article presents the results of calculations simulating the effects of nuclear elastic scattering for various test step wedges. Comparisons with experimental data are also presented. The traditional expressions of the transmission should be correct if the angle distribution of the scattering is Gaussian multiple Coulomb scattering. The mean free path（which depends on the collimator angle） and the radiation length are treated as empirical parameters, according to transmission as a function of thickness obtained by simulations. The results can be used in density reconstruction, which depends on the transmission expressions.
