Radon activity absolute measurement device

Abstract

The invention belongs to the technical field of radon activity absolute measurement, and specifically relates to a radon activity absolute measurement device. The device comprises an energy spectrum signal measurement and analysis system and an extremely low temperature measurement and control system, which are respectively connected with the top and bottom of a small solid angle measurement roomin a sealed manner. The device also comprises a diffusion-type solid radon source which is in sealed connection with one side of the small solid angle measurement room and provides radon gas for the interior of the small solid angle measurement room. The extremely low temperature measurement and control system can enable the radon gas in the small solid angle measurement room to be condensed intoa condensate radon source. The energy spectrum signal measurement and analysis system can carry out the small solid angle (alpha) measurement of the condensate radon source. The device also comprisesa vacuum measurement and control system for the vacuum pumping of the small solid angle measurement room and the extremely low temperature measurement and control system. The device can measure the energy spectrum and source geometric parameters of the same condensate radon source at the same time, and a detector is not liable to be polluted during multiple measurements, and obtains a standard radon source which does not depend on a radium source standard substance set value, thereby fundamentally improving the uncertainty level 2% (2*sigma) of radon measurement. Moreover, the operation is convenient, and there is no liquid source pollution danger.

Description

technical field [0001] The invention belongs to the technical field of absolute measurement of radon activity, and in particular relates to an absolute measurement device of radon activity. Background technique [0002] Radon, a radioactive inert gas, widely exists in nature and artificial building materials, and is one of the main sources (54%) of the natural environmental radiation that the human body is exposed to. According to different measurement purposes, various measurement methods have been applied. According to the sampling method, it can be divided into two categories: active type and passive type; according to the measurement method, it can be divided into instantaneous measurement, continuous measurement and cumulative measurement. Passive methods include TLD (thermoluminescence), activated carbon adsorption, STD (solid track), electret charge method, etc.; active methods include ionization chamber, LUCAS scintillation chamber, double filter membrane, balloon me...

AI Technical Summary

Problems solved by technology

[0005] In view of the current domestic radon measurement standards are relative standards, the problem of high measurement uncertainty

The purpose of this invention is to provide a kind of improved small solid angle method radon absolute measurement and radon gas source generation system, solve the energy spectrum and the source geometry parameter of measuring the same condensed radon source, and the problem that the detector is easy to pollute, obtain independent The standard radon gas source determined by the radium source reference material can fundamentally improve the uncertainty level of radon measurement by 2% (2σ), and it is easy to operate, and there is no risk of contamination from liquid source leakage

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