Design of Compact Shielding Device and Irradiator Based on ²⁴¹Am-Be Neutron Source

The ²⁴¹Am-Be neutron source is widely used in experimental research. Proper shielding needs to be designed to protect experimenters from neutron and gamma radiation. The energy spectrum distribution and dose value of neutrons transmitted through different materials were calculated by the Monte Carlo method to optimize the type and thickness of each layer of shielding material. A compact shielding device for ²⁴¹Am-Be neutron source is designed. The device protection adopts a four-layer combination of tungsten+polyethylene+borated polyethylene+stainless steel. The dose equivalent rate H*(10) around the outer surface is lower than 10 μSv/h, which meets the radiation protection requirements. The fluence distribution of thermal neutron, epithermal neutron and fast neutron in the device is studied to determine the best opening position of the fast neutron and thermal neutron output channel of this device. When the irradiation device simultaneously opens the fast neutron and thermal neutron channels for experimental testing, it is necessary to set up a control area with a distance greater than 130 cm to ensure the safety of the worker.