Scattering suppression detection structure for measuring low energy gamma rays on site

Abstract

The invention is mainly applied to the measurement of 241 Am low energy gamma rays on site, particularly to a scattering suppression detection structure for measuring the low energy gamma rays on site. A main detector is designed as a cylindrical well structure. A suppression detector is placed in the main detector in the shape of the cylindrical well. According to energy deposition distribution characteristics of low energy gamma, high-purity germanium HPGe with high resolution is selected as the main detector, a bismuth germanate BGO scintillation crystal with high detection efficiency is selected as the suppression detector. The suppression detector is designed as a cylindrical solid structure. The appropriate diameter D+2T and length L+T of the cylindrical well-shaped main detector areselected under a premise of satisfying portability requirements. The radial thickness T of a peripheral wall and a bottom of the main detector is uniformly selected within 2 to 9 mm. The diameter D and length L of the cylindrical suppression detector are determined by the dimensions of the diameter and length of the main detector. According to the scattering suppression detection structure for measuring the low energy gamma rays on site, the ability of measuring the low energy gamma rays on site is improved.

Description

technical field [0001] The invention relates to a new scattering suppression detection structure, which adopts anti-coincidence suppression technology and is mainly used in on-site measurement 241 Am low-energy gamma rays, in particular a scattering-suppressed detection structure for in-situ low-energy gamma-ray measurements. Background technique [0002] 241 The characteristic γ-ray energy of Am is low (59.54keV). When on-site measurement is performed in a site with complex types of polluting nuclides, it is easily affected by the high-energy γ-ray Compton scattering background of other nuclides, resulting in an increase in the detection limit. Unable to meet on-site measurement requirements. Anti-coincidence technology is the most effective method to suppress the scattering background. By suppressing the Compton scattering events during the action of gamma rays, the Compton continuum generated by high-energy gamma rays is reduced, and the measurement cost of low-energy g...

AI Technical Summary

Problems solved by technology

[0006] The invention adopts a detection structure in which the main detector surrounds the suppressing detector, solves the problem of low-energy gamma-ray detection efficiency reduction caused by the shielding effect of the suppressing detector, effectively suppresses the scattering background in the low-energy region, and improves the ability to measure low-energy gamma-rays on site

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