Probe Development Of Space Neutron Scintillation Detector

The space radiation environment will cause damage to spacecraft and astronauts in space missions,and even lead to the failure of space missions.The space radiation contains a variety of radiation particles,with the development of space mission,the cumulative radiation damage of neutron compared to other radiation particles are paid more attention,so the detection of space neutron is particularly importantIn this paper,a space-neutron detector probe based on plastic scintillator is designed,which includes the plastic scintillator model,size,the selection of guide angle and reflective layer,and with the high sensitivity,fast response time of the silicon photomultiplier tube(SiPM),the final electronic system with the back-end into a plastic scintillator space neutron detector system.Firstly,the optimal probe configuration was selected by the performance index of energy resolution.The calibration of the energy spectra was performed using the 60 Co and 137 Cs standard ? sources.The matching algorithm and event detection efficiency for the double signal output was studied.The best coincidence time for the 3cm × 3cm × 13 cm size plastic scintillator is 15 ns.Secondly,the scheme was tested with 252 Cf spontaneous fission neutron source.The pulse signal discrimination(PSD)method was used to process the n/? event analysis,PSD distribution can clearly see the reflection of n/? characteristics of the two particle bands,calculate the PSD projection FOM value of 1.12 also shows it has a good n/? discrimination ability.At last,two new techniques are proposed to improve the neutron discrimination ability: neutron enhancement technique and auxiliary detector anti-coincidence measurement technique.The effect of the substitution of Li2CO3 and GdO as neutron reinforcement materials with larger neutron reaction cross section,the neutrons react with GdO to produce a large number of ? events can play a good neutron enhancement around.The LYSO crystal which is more sensitive to charged particles is studied and used as a secondary detector.The anti-coincidence time window of the main and auxiliary detectors is measured by the anti-coincidence principle.The results show that the secondary detectors have a certain effect on charged particles in the main detector But the environmental background,electronic noise,statistical fluctuation and other interference to be further removed.