Accurate calibration method for alpha spectrometry peak overlap correction factor of radon daughter measuring instrument

Abstract

The present invention discloses an accurate calibration method for an alpha-spectrometry peak overlap correction factor of a radon daughter measuring instrument. A radon daughter measuring instrument samples from <220>Rn daughter measurement environment and stands, and then a channel value LV1, corresponding to an upper threshold of a <222>Rn daughter RaA (<218>Po) 6.0MeV spectrometry peak counting area, of the measuring instrument is calibrated by means of multiple channels. The radon daughter measuring instrument samples from pure <220>Rn daughter environment after refilled with a filter membrane. Alpha particle quantities N11 and N12 in a 6.0 MeV counting area and a 7.69 MeV counting area in the time period of 60-120 min are calculated by using the multiple channels, and a peak overlap factor theta1 is calculated. The radon daughter measuring instrument samples from pure <222>Rn daughter environment after the filter membrane is changed, and then a channel value LV2, corresponding to an upper threshold of a <222>Rn daughter RaC'(<214>Po) 7.69MeV spectrometry peak counting area, of the measuring instrument is calibrated by means of the multiple channels. The radon daughter measuring instrument samples from a <220>Rn chamber after being refilled with a filter membrane, alpha particle quantities N24, N23 and N22 are measured via a multi-channel pulse amplitude analyzer, and peak overlap factors theta2 and theta3 are determined.

Description

technical field [0001] The invention belongs to the technical field of radioactive inert gas measurement, and relates to an accurate calibration method for an alpha energy spectrum peak overlap correction factor of a radon daughter measuring instrument. Background technique [0002] radon (including 222 Rn and 220 Rn) is a radioactive noble gas and is one of the main sources of natural radiation exposure. but 222 Rn / 220 The contribution of Rn daughters to the dose due to the environment is much greater than that of 222 Rn / 220 Rn, "Radon harm" is actually the harm of radon daughters to the human body. In order to accurately evaluate the environment 222 Rn / 220 Doses and hazards caused by Rn and its daughters need attention 222 Rn / 220 Method and device for measuring Rn daughter body. [0003] Because the α energy spectrum method has the characteristics of good measurement accuracy, short measurement time, and strong retort ability, it is currently commonly used i...

AI Technical Summary

Problems solved by technology

However, sometimes due to long-term use or improper use, the electronic components in the instrument are gradually worn out or damaged, and the gain and parameter values ​​​​of the preamplifier and linear amplifier have changed compared with the calibration, resulting in energy drift.

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