Device and method for detection efficiency calibration of xenon sample HPGe

Abstract

The invention discloses a device and method for detection efficiency calibration of a xenon sample HPGe. The device comprises a radioactive source, a plurality of polyethylene boxes and a detector, wherein the polyethylene boxes are different in height and contain air samples. The radioactive source comprises a 133Ba surface source and a 137Cs point source. A surface area aluminum substrate is used as an upper absorption layer. The 137Cs point source is located in the central position on the upper surface of the 133Ba surface source. The 133Ba surface source is located above the polyethylene boxes containing the air samples. The upper surface and the lower surface of each polyethylene box are used as lower absorption layers. The detector comprises a crystal, an aluminum outer shell and a carbon material window, wherein the aluminum outer shell is located outside the crystal, and the carbon material window is located on the aluminum outer shell and located above the crystal. The polyethylene boxes are placed above the window of the detector. According to the device and method for detection efficiency calibration of the xenon sample HPGe, the height of the adopted radioactive source is increased in an evenly-spaced mode, the 133Ba surface source is used for replacing a 133Xe sample to conduct efficiency calibration, the peak efficiency of the 137Cs point source is used for correcting correction factors conforming to the addition of the peak efficiency of the 133Ba surface source, and the technical problems that an existing detection efficiency calibration method is quite high in requirement for activity of the source, the self-absorption problem exists in rays, and larger uncertainty exists are solved.

Description

technical field [0001] The invention belongs to the technical method of radiation detection, and specifically relates to 133 Surface source efficiency calibration technology for detection efficiency of Xe gas and correction technology for cascading radioactive sources to meet additive effects. Background technique [0002] The Comprehensive Nuclear-Test-Ban Treaty primarily uses radionuclide monitoring to implement and monitor various nuclear tests. In a nuclear explosion, four radioactive xenon isotopes are produced in large quantities: 131m Xe(t 1 / 2 =11.84d), 133 Xe(t 1 / 2 =5.243d), 133m Xe(t 1 / 2 =2.19d), 135 Xe(t 1 / 2 =9.14h), these nuclides are relatively easy to be detected within a few days of a nuclear explosion due to their long half-life, and the gas nuclides of international focus are 133 Xe gas, so its monitoring technology has become the focus of research in various countries. general measurement 133 Xe gas adopts β-γ coincidence method and HPGeγ energy ...

AI Technical Summary

Problems solved by technology

[0010] The purpose of the present invention is to provide a 133 Ba surface source simulation scale 133 The method of HPGe detection efficiency of Xe samples, which solves the technical problems of the existing detection efficiency calibration method that requires very high source activity, self-absorption of rays, and large uncertainty

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