Moisture-proof and stain-resistance gas-flow ionization chamber detector

Abstract

The invention belongs to the field of nuclear radiation monitoring and provides a moisture-proof and stain-resistance gas-flow ionization chamber detector, which comprises a gas nozzle, a spring, insulation supports, a collection electrode assembly, a collection electrode wiring column, a high voltage electrode wiring column, a gas outlet, thin-walled pipeline supports, a thin-walled pipeline array, a collection electrode sealing assembly, a guide flow plate, a detector shell, a gas inlet, a balance gas bag and the like. A detected gas flows through the middle thin-walled pipeline, ionizationrays in the detected gas penetrates through the ionization working gas in the thin-walled pipeline, free charges are generated, the free charges drift to two electrodes under effects of an electric field, current is formed, and the current signal is proportional to the radioactivity concentration of the detected gas. The scheme of isolating the electrodes from the detected gas is adopted to comprehensively enhance the environmental adaptability of the detector, the leakage current of the collection electrode is extremely low, and the ability to measure weak radioactivity by the detector is enhanced. The detector has the ability to be used in high radioactivity, high temperature, high humidity and high voltage extreme environments.

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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