Method for controlling radon concentration of Rn/Tn mixed radon chamber

Abstract

The invention discloses a method for controlling the radon concentration of an Rn / Tn mixed radon chamber, and in particular relates to a method for quantitatively controlling the concentration of two radioactive gases 222Rn and 220Rn in the Rn / Tn mixed radon chamber simultaneously. The technical scheme of the invention comprises the following steps of: setting expected concentration of radon and thoron and a maximum error which is allowed to be controlled by a user; calculating thorium removing rate, radon removing rate, exhaust gas flow, first radon supplementing duration, attenuation duration and second radon supplementing duration; and performing control operation such as first radon supplementing, attenuation, second radon supplementing, attenuation and the like in turn according to time parameters. By the control method, the stability of the two radioactive gases 222Rn and 220Rn in the radon chamber is ensured and the influence of radioactive statistical fluctuation is also eliminated; and automatic control is easy to realize. The method can be widely applied to the accuracy control of the radon concentration of various Rn / Tn mixed chambers.

Description

technical field [0001] The present invention designs a kind of control method of radioactive gas concentration, more specifically refers to a kind of in Rn / Tn mixing type radon chamber, to 222 Rn and 220 A method for simultaneous quantitative control of the concentration of two radioactive gases, Rn. Background technique [0002] Radon gas (mainly refers to 222 Rn and 220 Rn, referred to as radon and thoron) is one of the 19 major environmental carcinogens and the most direct radioactive threat. In order to study the radiation hazards and biological effects of radon and its progeny on animals and plants, the various demands for radon measurement are constantly increasing, and various radon measurement technologies and instruments emerge in endlessly, and the radon measuring instrument indirectly obtains radon and Instruments for daughter concentration. All radon measuring instruments must be calibrated, and can be used normally only after the traceability of the val...

AI Technical Summary

Problems solved by technology

For uranium series, the previous generation nuclides of radon 226 Ra (isotope of radium) is a long-lived nuclide that can be used as a parent, and its decay 222 Rn (the isotope of radon, referred to as Rn emanation for short) is also a long-lived nuclide, so it is easier to achieve dynamic stability and uniform distribution of radon chambers of different volumes; 224 Ra (isotope of radium) is a short-lived nuclide that is difficult to use as a parent, and can only be used 232 Th (thorium parent element) as the parent nuclide, and the decay produced 220 Rn (the isotope of radon, referred to as Tn emanation) is an extremely short-lived nuclide, and it is difficult to achieve dynamic stability and uniform distribution of radon and daughters in large and medium-sized radon chambers

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