基于微通道板的中子探测器γ射线灵敏度

A new ultrafast pulse neutron detector based on MCP is introduced. The γ-ray sensitivity of the detector was investigated through simulation and experiment. A model of theoretical simulation was set up for γ-ray sensitivity calculation. In this model, the energy spectra and emitting angle distribution of electrons which were produced by different energy's γ-ray injecting into the different thickness' polyethylene were calculated through Monte Carlo methods. Then, the yields of secondary electrons produced by the single electron injecting into microchannel of MCP were also calculated through the experiential formula. The γ-ray sensitivity of the detector was finally obtained. The results shown that the γ-ray sensitivity of the detector was almost constant when the thickness of polyethylene was above a certain value. Some experiments were performed to test the γ-ray sensitivity at the standard gamma ray sources of Northwest Institute of Nuclear Technology. The simulated results agree with the results of experiments considering the uncertainties.