LYSO Crystal And Fast Plastic Scintillator Combination Detection Technology

Neutron detection is an important subject in the study of space radiation field.Neutron has an important impact on space activities.Neutron measurement is necessary in critical space,manned space flight and deep space exploration.Damage caused by neutrons and secondary neutrons to the aircraft,electronic devices and astronauts performing missions cannot be ignored.Therefore,it is necessary to study and detect space neutrons.The space environment is a mixture of radiation fields,and the measurement conditions are also complicated.Only one single neutron detector is less frequently used due to its limited function.Combined neutron detectors are needed to detect and identify neutrons more accurately.The purpose of this paper is to detect and identify neutrons in space.Two detector units of different materials are built and tested.The performance of the detector system is studied based on conformance measurement technology.The main contents of this paper include:Firstly,design and test the detector unit.Based on performance indexes such as energy resolution and light collection efficiency,a LYSO crystal detector unit and a fast plastic scintillator detector unit were built.The detector unit is energy-scaled using ⁶⁰Co and ²²Na standard gamma sources.The LYSO crystal has an energy resolution of 15.9%for 511KeV photons.Secondly,combining LYSO and fast plastic detector units can form a fast and slow scintillation detector for detection.The beta spectrum combined with low-energy electrons and high-energy electrons is obtained,and the high-energy segment is better.The combined detector is tested by simulating the environment of charged particles in space.According to the anti-coincidence measurement principle,the anti-coincidence time window of the fast plastic detection unit was opened,and the neutron spectrum obtained was in good agreement with the theoretical energy spectrum,indicating that the combination detector anti-coincidence correlation inhibited the interference of charged particles to some extent.Finally,combining two fast plastic detector units to form a measurement system for the flight time spectrum of the D-T neutron generator.?-n time correlation was performed on the true events recorded by the two units.Through the multiple correlation time selection of the combination detector,the n peak and?peak can be clearly distinguished,achieving the purpose of n/?discrimination.