Low-background spectrum unscrambling method based on sodium iodide detector

Abstract

The invention discloses a low-background spectrum unscrambling method based on a sodium iodide detector. The method comprises the following steps: (1) a gamma detector after energy calibration actually measures a radionuclide spectrum and a natural background spectrum, and noise reduction is carried out; (2) a deconvolution algorithm is adopted to process a gamma energy spectrum after noise reduction; (3) a peak searching algorithm carries out searching on all potential peak positions of the gamma energy spectrum after noise reduction, and a peak position list is acquired; and (4) the peak position list information and a nuclide library are combined to be together inputted to a fuzzy logic system, the system gives the peak position recognition confidence for any nuclide characteristic peakin the nuclide library, constraints are set to further adjust the peak position recognition confidence, and thus, a nuclide list and the nuclide recognition confidence are acquired. The low-background spectrum unscrambling method based on the sodium iodide detector has the advantages of accurate peak position reduction, remarkable improvement of energy resolution, decomposition of an overlapped peak, low error recognition rate, accurate background nuclide analysis and accurate low activity nuclide analysis, and can be used for nuclide recognition and activity calculation for radiation monitoring equipment such as a gated radiation monitor and a nuclide recognition instrument.

Description

technical field [0001] The invention relates to a gamma energy spectrum analysis method, in particular to a low-background analysis method based on a sodium iodide detector. technical background [0002] After the rapid nuclide identification, as the measurement time increases, the basic shape of the gamma energy spectrum needs to use mathematics, physics or a combination of both methods to conduct high-precision analysis of the measured energy spectrum to achieve accurate nuclide identification. [0003] At present, most of the detectors used for nuclide identification are semiconductor detectors, such as high-purity germanium detectors. However, due to the characteristics of semiconductor detectors, they need to be refrigerated, expensive, and bulky, making them unsuitable for application. Under the complex environment, it is used for nuclide identification tasks, and detectors with low energy resolution, such as sodium iodide detectors, have serious overlapping peaks, and...

AI Technical Summary

Problems solved by technology

[0003] At present, most of the detectors used for nuclide identification are semiconductor detectors, such as high-purity germanium detectors. However, due to the characteristics of semiconductor detectors, they need to be refrigerated, expensive, and bulky, making them unsuitable for application. Under the complex environment, it is used for nuclide identification tasks, and detectors with low energy resolution, such as sodium iodide detectors, have serious overlapping peaks, and the processing measures for overlapping peaks will directly affect the accuracy of the final results and Reliability, that is, incorrect decomposition of overlapping peaks will lead to misidentification of nuclides and inaccurate calculation of nuclide activity, which in turn will lead to wrong assessment of surrounding radiation levels, threatening the safety of human property

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