High-sensitivity alpha energy spectrum measuring method of radon concentration in air

Abstract

The invention discloses a high-sensitivity alpha energy spectrum measuring method of radon concentration in air by using a radon and daughter collecting device, an alpha ray semi-conductive detector, a temperature and humidity measuring module, a circuit system, a man-computer interface and a computer data analysis system. The sensitivity surface of the alpha ray semi-conductive detector is arranged in a cavity of the radon and daughter collecting device, and the alpha ray semi-conductive detector, the temperature and humidity measuring module and the man-computer interface are connected with the circuit system which is connected with the computer data analysis system through a USB (Universal Serial Bus) interface. The method collects radon in the air by adopting a static diffusion mode, absorbs radon charged daughters by adopting a high-pressure electrostatic mode, distinguishes radon-thorium daughters by utilizing the alpha ray semi-conductive detector to measure air radon concentration through alpha energy spectrum measurement and correct influence on the measurement of radon concentration by adopting a temperature-humidity synchronous measuring mode. The method is suitable for the fields of monitoring radon level and controlling pollution in the indoor radiation environment of civil constructional engineering, monitoring radon concentration in mines and tunnels, and the like.

Description

technical field [0001] The invention relates to a method for measuring radon by alpha energy spectrum and a corresponding device, in particular to a highly sensitive method for measuring radon concentration in air by alpha energy spectrum which can realize the measurement and analysis of radon concentration in air. Background technique [0002] Radon is a gaseous radionuclide in the natural radioactive decay series, and its decay product is a non-volatile radioactive substance. Once inhaled into the human body, it will cause damage to the human lungs and increase the possibility of inducing lung cancer. According to statistical research, indoor radon pollution is the second largest cause of lung cancer after smoking. To this end, the country has issued the national standard GB50325-2001 "Code for the Control of Indoor Environmental Pollution in Civil Construction Engineering" and the national standard GB / T18883-2002 "Indoor Air Quality Standards", which stipulate the require...

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Problems solved by technology

[0003] Existing radon measuring instruments, such as α-track radon measuring, natural thermoluminescence radon measuring, activated carbon radon measuring, air pulse ionization chamber measuring radon, etc., are difficult to measure radon with alpha energy spectrum, so it is impossible to distinguish between radon and radon. The energy spectrum characteristics of its daughters are also affected by the ambient temperature and humidity, the measurement value has a large uncertainty, and the sensitivity is relatively low, which limits people's further understanding of the environmental radon hazards.

Due to the use of α total measurement, the measurement is affected by the radon daughter equilibrium time (more than 4 hours), generally requires a long cumulative measurement time, which does not meet the requirements for measurement speed applications

Although the RAD7 pump-suction α-energy spectrum radon meter produced in the United States already exists, because it adopts a dynamic pump-suction method, when measuring the radon concentration in the air, the radon gas field in the measurement environment is greatly disturbed, so the measurement results are inaccurate. It is relatively large, and its measurement sensitivity is not high enough. At the same time, the mechanical structure of the instrument system is relatively complicated, expensive, large in power consumption, and large in size, so it is inconvenient to use

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