Measurement of Reference Radiation Spectrum of Isotopic Neutron Source and Analysis of Simulated Neutron Spectrum

The neutron reference radiation field of different components is the basic condition for the performance test of neutron shielding materials. In order to obtain an ideal neutron field for neutron protection material testing, a multi sphere energy spectrum measurement system based on ³He tube was constructed. The neutron radiation field slowing down condition based on ²⁴¹Am-Be and ²⁵²Cf neutron sources was simulated and the energy spectrum was measured. In order to accurately judge the neutron scattering at the calibration reference position of the laboratory, the neutron scattering component measurement was carried out based on the multi sphere neutron spectrum measurement system. The dose rate conversion of the energy spectrum was carried out using the dose dose conversion coefficient recommended by ICRP. Compared with the results of the long counter, it was found that the deviation of the dose rate at the calibration position was not more than 20%. The experimental study on obtaining specific energy spectrum of polyethylene moderated isotope neutron source was carried out. The simulated calculation and experimental measurement of moderated spectrum were carried out, and the results were in good agreement. This work provides a useful neutron radiation field for the subsequent neutron metrology test and neutron protection material test.