Design of a neutron shielding performance test system base on Am–Be neutron source

A system for neutron shielding performance test was designed based on an Am–Be neutron source and 3He proportional counter. The Am–Be neutron source was shielded by paraffin wax block with a thickness of dozens of centimeters and collimated by polyethylene rod. The neutron energy spectra in front of the collimator were simulated by MCNP. The detector system was designed based on 3He proportional counter and different response tuning assembly (RTA) to optimize the neutron energy region of interest. A method for testing neutron shielding performance for thermal, epithermal, fast neutrons and neutron ambient dose equivalent rate was proposed by employing different response tuning assembly (RTA). Common radiation shielding materials including polyethylene (PE), borated polyethylene (BPE) and graphite were conducted with the designed system. The results demonstrated that the proposed method is efficient for investigating the neutron shielding performance of materials.