Corrective LED spectrum-stabilization device based on program-controlled constant-current source and photodiode, and method thereof

Abstract

The invention relates to the technical field of nuclear instruments, and in particular relates to a corrective LED spectrum-stabilization device based on a program-controlled constant-current source and a photodiode, and a method thereof, used for solving the spectrum line drift problem to a scintillator-based energy spectrum detection system due to temperature change. The program-controlled constant-current source is controlled by a main controller to drive an LED, so that an optical pulse signal capable of simulating photon emission after a gamma ray is absorbed by a scintillator is generated; a spectrum line peak position generated by LED optical pulse can be obtained in a gamma energy spectrum detected by the energy spectrum detection system; drift of the LED light emission amount along with temperature change is corrected through a photodiode path; then, the gain is adjusted by utilization of the corrected LED peak position as the spectrum line reference peak, so that spectrum stabilization is carried out; temperature drift of a photomultiplier and electronics is eliminated; finally, the gain is adjusted again by calling in of a scintillator photoyield temperature change curve; and thus, temperature drift of the scintillator is eliminated. Precise spectrum stabilization of the scintillator energy spectrum detection system in different temperature conditions can be realized.

Description

technical field [0001] The invention relates to the technical field of nuclear instruments, in particular to an LED spectrum stabilization device based on a program-controlled constant current source and photodiode correction and a method thereof. Background technique [0002] After the scintillator absorbs the gamma ray, it can emit different amounts of fluorescent photons according to the energy of the gamma ray within a fixed light decay time. Fluorescent photons are collected by photomultiplier devices to generate pulse signals of different amplitudes. The pulse amplitude obtained by different gamma rays is different, and the spectral analysis based on the pulse amplitude is called gamma energy spectrum measurement. Gamma spectrum measurement is widely used in radioactive geological prospecting, environmental radiation monitoring, cosmic ray monitoring, nuclear radiation emergency measurement and other fields. Spectrum stabilization is both a difficulty and an importan...

AI Technical Summary

Problems solved by technology

At this time, the spectral drift elimination method (characteristic peak method, spectral feature matching method, spectrum method) using the natural background spectral line characteristics cannot accurately and effectively eliminate the spectral line drift; the method of using the radioactive source method to stabilize the spectrum has the loss of radioactive sources The risk of polluting the environment; the use of the constant temperature law requires the design of a complex heat preservation and heat dissipation system, especially in the large crystal energy spectrum detection system, the design of the heat preservation and heat dissipation system is more complicated

[0005] If the LED is directly driven, the generated optical pulse signal cannot meet the accuracy requirements of the stable spectrum. At the same time, the luminous intensity of the LED will decay with the prolongation of the use time, which needs to be corrected regularly, which is complicated and cumbersome, and cannot be effectively used to eliminate the spectrum. line drift

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