铝箔分辨法测量钍射气研究

Study on the Performance of Discriminating Method Using Aluminum Foil to Measure Thoron Concentration

为了实现^(222)Rn和^(220)Rn的分辨测量,研究确定了α射线损失能量与铝箔阻挡厚度的关系,利用氡子体发射的6.00 MeV(218Po)和7.69 MeV(214Po)α射线进行了实验验证,并确定了氡钍分辨的铝箔较优阻挡厚度为46.60μm。将包裹该厚度铝箔的探测器置于220Rn室内开展照射实验,得到钍射气及其子体的刻度系数分别为0.53 Tr·cm^(-2)/(k Bq·m^(-3)·h)和7.3 Tr·cm^(-2)/(k Bq·m^(-3)·h)。建立的铝箔分辨法可有效用于222Rn和220Rn的分辨测量。

To measure Thoron concentration, the relationship was established between loss energy of α- ray e- mitted by 241 Am and thickness of aluminum foil which was also demonstrated by 6.00 and 7.69 MeV of α- ray emitted by Radon progenies 218Po and 214Po separately. The optimized resist thickness of aluminum foil is 46.60 μm,with which the calibration factors of Thoron and its progenies is 0.53 Tr cm-2/（kBq m-3 h） and 7. 3 Tr cm-2/（ kBq m-3 . h） determined by the experiment of exposure in Thoron chamber and Thoron proge- ny chamber. The method established in this paper can discriminate between Radon and Thoron efficiently.