Multiple NaI (T1) detectors based radioactive substance two-dimensional locating method

Abstract

The invention discloses a multiple NaI (T1) detectors based radioactive substance two-dimensional locating method in an access control detection system. A two-dimensional locating model of a radioactive substance is determined through the measurement of the attenuation law of gamma rays and the change of the azimuth angle of the radioactive substance at different positions relative to a detector. The energy resolution capability of the NaI detector is utilized to recognize the radioactive nuclide, and the problems of mutual interference of different radioactive nuclides and simultaneous location of different radioactive substances can be effectively solved under a multi-source condition. According to the method, a maximum characteristic peak counting detector with high counting capability, a detector at the opposite side and a second largest characteristic peak counting detector at the opposite side are adopted, situations that the location error is increased and even a position close to the edge cannot be located due to the influence of statistical fluctuation on the counting value of the detector when the solid angle of the radioactive substance on the detection surface of the detector is too small or the attenuation distance is overlong are avoided, and the method has the advantages of short measurement time, high location accuracy and the like.

Description

technical field [0001] The invention relates to a radioactive material positioning method, in particular to a radioactive material two-dimensional positioning method based on a plurality of NaI(T1) detectors. Background technique [0002] The peaceful use of radioactive materials is a great asset to mankind, but if the radioactive materials leak and spread, it will also cause unimaginable harm to human society. The gamma radioactive portal system is a gamma radioactive substance detection system suitable for radioactive sensitive areas. Plastic scintillator detectors are used to initially detect radioactive substances in and out of personnel and articles; NaI(Tl) detector arrays are used for further gamma energy spectrum measurement for personnel carrying radioactive substances. [0003] At present, the positioning of radioactive substances in and out of nuclear sites is mainly through multi-counter positioning and manual search positioning. Multi-counter positioning uses ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a radioactive material two-dimensional positioning method based on multiple NaI(T1) detectors, which solves the problem of multi-source positioning in multi-counter positioning, and overcomes the problem of multiple counters in the prior art. There is no need to manually search and locate the defect that cannot be located in the case of multiple radioactive substances in different positions, which avoids the time for the staff to be irradiated, and has the advantages of short measurement time and high positioning accuracy

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