Novel large-area thermal neutron detector

Abstract

The invention relates to a novel large-area thermal neutron detector which comprises an upper reflecting layer, a lower reflecting layer, a wave-shifting light guide and lithium glass scintillators, the wave-shifting light guide is located between the upper reflecting layer and the lower reflecting layer, and the lithium glass scintillators are distributed inside or on the surface of the wave-shifting light guide. The wave shift light guide is used for transferring the wavelength of fluorescence emitted by the lithium glass scintillator to a blue-green light long wave band. The sensitive area is increased by introducing a wave shift technology, so that a high-performance and large-size 3He tube is developed based on the lithium glass scintillator to replace a detector.

Description

Technical field [0001] The invention relates to the technical field of neutron detection, in particular to a novel large-area thermal neutron detector based on lithium glass scintillator and wave shift technology. technical background [0002] For a long time, neutron detection technology has been an important means of nuclear radiation safety monitoring, among which 3 With excellent performance, the utilization rate of He tube in neutron detection is as high as 75%. At present, in the rapidly developing nuclear power industry, border port security and material structure research, etc. 3 He tubes are widely used, such as scattering neutron spectrometer and nuclear safety monitoring system, all of which use large-scale 3 He detection array. But in recent years, international 3 Due to the serious shortage of resources, the price of He gas has soared, and it needs to be developed urgently. 3 A new neutron detector replaced by He tube, which is based on 6 The research and development...

AI Technical Summary

Problems solved by technology

But for a long time, lithium glass has two main problems: one is due to 6 The thermal neutron peak equivalent electron energy of Li glass is about 1.5MeV, which leads to its high sensitivity to high-energy gamma. It is necessary to reduce the particle size of lithium glass to reduce the gamma deposition energy. In theory, lithium glass can be processed to 280μm~ A 1mm filament, fiber or particle can reduce its gamma sensitivity to 10 -6 ~10 -3

two is 6 The fluorescence yield of Li glass is low (6000pe) and the wavelength is in the near ultraviolet region, which leads to a short attenuation length of light transmission, which limits the increase of the sensitive area of ​​the detector.

The above two shortcomings make it possible to develop high-performance, large-size lithium-ion glass based on lithium glass. 3 The process technology of He tube to replace the detector is relatively difficult, which is also the key direction of research and research at home and abroad

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