热释光氡子体个体α剂量计的研制与现场试验

有源式热释光氡、子体个体α剂量计现已研制成功。该剂量计采用超薄型CaSO_4·Tm热释光片,对α辐射的探测灵敏度高于其它氡子体剂量计,而对γ辐射的响应仅为0.8(读数/mR)。因此,探测下限低至1.04μJ·m~(-3)·h(0.05WLh) (γ本底1mR/h;取样周期6h)。取样头中装有三片CaSO_4·Tm,氡、子体暴露量可分别测定。取样泵中虽未装自动调流装置,但流率-阻力特性良好。自1981年以来,该剂量计在实验室和现场经过一系列试验,证明性能良好。本文着重概述了该剂量计的原理,特点及现场试验结果。

DEVELOPMENT AND FIELD TESTING OF THERMOLUMINESCENT PERSONAL a -DOSIMETER FOR MEASURING EXPOSURE TO RADON AND THORON DAUGHTERS

An active thermoluminescent personal alpha dosimeter for measuring exposure to radon and thoron daughters has been developed. The TL-chips mounted jn the dosimeter are ultra-thin CaSO4-Tm chips which are more sensitive to alpha radiation than those used in the other radon daughter dosimeters. The response of the chip to gamma radiation is decreased to such a level as 0.8 counts/mR, so the lower detection limit is reduced to 1.04 uJm-3h (0.05 WLh) (r background 1 mR/h; sampling period 6 hrs) Exposures to radon daughters and to thoron daughters can be determined separately by mounting three of those chips in the sampling probe of the dosimeter. The compact sampling pump, without flow regulator, features a satisfactory flow-resjstance characteristics. The prototype units have been subjected to a series of tests jn laboratory and fields since 1981. The testing results are summarized jn the paper.