Lane-Smith D, Wong F K
DURRIDGE Company, Inc., Billerica, MA 01821-2812, USA
Department of Mechatronics Engineering, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.
Radiat Prot Dosimetry. 2016 Oct;171(2):179-180. doi: 10.1093/rpd/ncw054. Epub 2016 Mar 23.
To determine the dose received by thoron (Rn) domestically, conventional methods measure the activity concentration of thoron progeny only (namely the Pb atoms) and calculate the dose by using a set of conversion factors. This may be due to the measurement of progeny being simpler since it is longer lived and will be evenly spread throughout the room, whereas the thoron gas, with its short half-life, will exist only near the source and hence will not be of major concern for the majority of the room. However, concrete walls are a source of thoron, and spending prolonged amounts of time near them may lead to greatly increased radiation exposure, the degree of which is not revealed through progeny activity alone. The present paper compares the energy received from the ionising radiation of both thoron gas and thoron progeny near its source. Converting the energy dose to radiation dose is not within the scope of this paper. The results suggest a difference of an order of magnitude higher when taking into account the dose received by thoron gas.
为了确定国内钍射气（Rn）的剂量，传统方法仅测量钍射气子体（即铅原子）的活度浓度，并使用一组转换因子来计算剂量。这可能是因为子体的测量更简单，因为它寿命更长，会均匀地散布在整个房间中，而钍射气气体半衰期短，只会存在于源附近，因此对于房间的大部分区域来说不是主要关注点。然而，混凝土墙是钍射气的一个来源，长时间在其附近停留可能会导致辐射暴露大幅增加，而仅通过子体活度并不能揭示这种增加的程度。本文比较了在源附近钍射气气体和钍射气子体的电离辐射所接收的能量。将能量剂量转换为辐射剂量不在本文范围内。结果表明，考虑到钍射气气体所接收的剂量时，差异会高出一个数量级。
