Manufacturing process of closed-gas large-area proportional counter used for measuring alpha and beta radioactive surface contamination

Abstract

The invention belongs to the field of nuclear radiation detectors, and particularly relates to a manufacturing process of a closed-gas large-area proportional counter used for measuring alpha and beta radioactive surface contamination. The manufacturing process comprises the following steps: designing the shell of a detector, selecting manufacturing materials, cleaning and passivating the materials, assembling and fixing the shell of the detector, cleaning an incident window, cleaning and fixing anode wires, pasting the incident window, displacing gas, performing sealing, and finally testing all performance indexes. The manufacturing process is simple and feasible and does not need special equipment; the closed-gas large-area proportional counter manufactured through the manufacturing process is still virgin ground in domestic proportional counters; according to the finished closed-gas large-area proportional counter manufactured through the manufacturing process, the plateau length can reach 200V under the plateau slope of 5% per 100V, the efficiency of measuring a 90Sr-90Y beta radioactive source and a 239 Pu alpha radioactive source respectively in the mode of tightly attaching to the surface of the incident window is more than 70% and more than 30% respectively, counting life is not shorter than 1.0E12, and shelf-life is more than one year. Thus, the proportional counter can get rid of the limit on a gas cylinder and on the gas circuit facilities of the gas cylinder when used in the alpha and beta radioactive surface contamination; besides, from the point of view of technology and use, a closed-gas proportional detector has the advantages of both a solid state detector and a gas-flow proportional detector.

Description

technical field [0001] The invention belongs to the field of nuclear radiation detectors, and in particular relates to a manufacturing process of an air-tight large-area proportional counter for measuring alpha and beta radioactive surface pollution. Background technique [0002] At present, most of the gas detectors used for the monitoring of large-area α and β radioactive surface contamination are flow-type proportional counters. Compared with solid detectors and gas-closed proportional counters, gas flow proportional counters have a significant technical defect: they must continuously provide new working gases (inert gases) during use, which requires gas cylinders and other gas circuits in process design facilities, which limit the scope of use of flow-type proportional counters in the monitoring of α and β radioactive surface contamination. For example: due to the need for gas cylinders and other gas circuit facilities, in portable α, β radioactive surface pollution mon...

AI Technical Summary

Problems solved by technology

Compared with solid detectors and gas-closed proportional counters, gas flow proportional counters have a significant technical defect: they must continuously provide new working gases (inert gases) during use, which requires gas cylinders and other gas circuits in process design Facilities, which limit the scope of use of flow-type proportional counters in the monitoring of α and β radioactive surface contamination

For example: due to the need to be equipped with gas pipeline facilities such as gas cylinders, flow gas proportional counters are rarely used in portable α and β radioactive surface pollution monitoring instruments; environmental factors affect the inhomogeneity of gas flow also have a greater impact on detection results