Experimental design of spherical deep penetration shielding benchmark and the effect verification

To address the lack of benchmark experimental data for verifying autonomous shielding calculation programs and databases, this study designed a series of spherical deep penetration shielding benchmark experiments using a Cf-252 neutron source. A shadow cone system was devised to address the critical challenge of subtracting scattered neutrons in these experiments. The scattering neutrons were effectively accounted for by comparing measurements taken before and after installing the shadow cone system. The Monte Carlo method confirmed the effectiveness of the shadow cone system, whereas the overall experimental setup was validated through tests with a bare neutron source. The results showed that the shadow cone system performed well in reducing scattering effects, with a maximum relative deviation of only 3. 11% in the detector response after subtraction. The energy spectrum measurement results from the bare source experiment aligned closely with the watt spectrum of the spontaneous fission neutrons of Cf-252, achieving a root-mean-square error of 1. 89×10^-3 in the 47 energy group spectrum. In conclusion, the deep penetration shielding benchmark experiments successfully met their objectives. The experimental data generated will support the verification of autonomous shielding calculation programs and shielding databases, contributing to the development of a comprehensive deep penetration shielding benchmark database for China.

Duke Scholars

Author Sifan Liu Statistical Science