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一、引言任何测定低水平环境辐射的仪器,仪器自身的放射性本底是需要认真考虑的问题之一,因为在低照射量率情况下,它直接影响仪器读数的准确度。就电离室而言,电离室内壁材料高原子序数杂质的α发射是电离室自身本底的主要来源。早期的工作就已注意到电离室材料的放射性污染。减小常压电离室室壁α发射影响的主要措施有:1)增大电离室体积,2)电离室内部改充负电性气体
I. INTRODUCTION Any instrument that measures low levels of ambient radiation, the instrument’s own radioactive background, is one of the issues to be carefully considered because it directly affects the accuracy of instrument readings at low exposure rates. In terms of the ionization chamber, the alpha emission of high atomic number impurity in the material of the ionization chamber wall is the main source of the ionization chamber’s own background. Earlier work had noticed radioactive contamination of ionization chamber materials. The main measures to reduce the emission of atmospheric pressure chamber wall α are: 1) increase the ionization chamber volume, 2) change the interior of the ionization chamber to charge the negative electrical gas