A moisture-proof and anti-contamination gas flow ionization chamber detector

Abstract

The invention belongs to the field of nuclear radiation monitoring, and provides a moisture-proof and anti-contamination flow-type ionization chamber detector, which includes a gas nozzle, a spring, an insulating support, a collecting electrode assembly, a collecting electrode terminal, a high-voltage electrode terminal, an air outlet, a thin Wall pipe supports, thin-wall pipe arrays, collecting electrode sealing components, deflectors, detector housings, air inlets, balance airbags, etc., the measured gas flows through the middle thin-walled pipes, and the ionized rays in the measured gas The ionized working gas that penetrates the thin-walled pipeline generates free charges, and the free charges drift to the two poles under the action of the electric field to form a current, and the current signal is proportional to the radioactive body activity concentration of the measured gas. The invention adopts the scheme of isolating the electrode from the gas to be measured to comprehensively improve the environmental adaptability of the detector, the leakage current of the collector is extremely low, and the ability of the detector to measure weak radioactivity is enhanced. The detector of the invention has the ability to be used in extreme environments of high radioactivity, high temperature, high humidity and high pressure.

Description

technical field [0001] The invention belongs to the field of nuclear radiation monitoring, and in particular relates to a moisture-proof and anti-contamination gas flow type ionization chamber detector. Background technique [0002] The ionization chamber is a gas detector working in the saturation region. In principle, there is neither charge recombination nor gas amplification. All electrons and positive ions generated by the ionization of incident particles are collected on the positive and negative electrodes. There are two types, one is a pulse ionization chamber that records a single nuclear radiation particle, and the other is a current ionization chamber that records the average ionization effect of a large number of particles. [0003] In the field of nuclear power at home and abroad, the flow-type ionization chamber is mainly used to measure the β-radioactive gas with high body activity concentration, and there is no report on the flow-type ionization chamber that ...

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Problems solved by technology

[0005] The above-mentioned existing flow-type ionization chamber detector has the following disadvantages: when the measured gas temperature and humidity are high, the moisture in the air may condense on the surface of the collector insulator, resulting in insulation between the collector and adjacent components. The resistance drops, which leads to the distortion of the measurement signal; as the ventilation time increases, the dust in the measured gas will also deposit on the surface of the collector, and the insulation resistance of the collector insulator will also be affected; if the dust deposited inside the detector contains radioactivity, it will make the detection The background count of the detector rises, especially the α radioactive dust contamination may cause the detector to have a large output signal for a long time, or even exceed the alarm threshold, resulting in inaccurate measurement of gas radioactivity and reducing the reliability of the equipment. When measuring high-temperature and high-humidity gas, the measured gas itself also has charge transfer capability, which will generate a large leakage current, which will make the performance of the detector worse, such as: the lower limit of detection is raised, and the detection accuracy becomes lower. Poor, endangering the safety of users' life and property, etc.

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