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利用热释光测定陶片年代时,要准确地测出古陶器中所积存的热释光剂量,这首先就必须测准产生这一剂量的、存在于陶片中的天然放射性物质的含量。这是热释光对陶片断代研究中的一个重要环节。U、Th、~(40)K、~(87)Rb是天然存在的放射性核素,它们的放射性所给予陶片的年剂量率列于表1。自表1看出,在这五个天然放射性母核中,铀对年剂量率贡献最多。~(238)U的天然丰度极大,在铀系中,氡是一种气体,它有可能从陶片中逸散。从表2看出,氡及其子体对年剂量率的贡献占了很大的比重。因此,在决定年剂量率时,氡的逸散与否,确实是关键之一。V.S.Desai等根据氡在土壤中移动的情况,安排了一个测定陶片中氡的实验,结果认为在土壤干燥条件下氡的逸散高达40％,而在潮湿的情况下,由于氡的溶解,逸散减少。此外,氡的逸散程度也与陶片类型有关。
To determine the amount of thermoluminescence accumulated in ancient pottery when thermochronometry was used to determine the age of the pottery, it was first necessary to determine the amount of natural radioactive material present in the pottery that produced this dose. This is an important part of the study on the cementation of ceramsite. U, Th, ~ (40) K, ~ (87) Rb are naturally occurring radionuclides whose annual dose rates given for their radioactivity are listed in Table 1. As can be seen from Table 1, uranium contributes the most to the annual dose rate among the five natural radioactive mother nuclei. The natural abundance of ~ (238) U is extremely high. In uranium, radon is a gas that is likely to escape from the clay. As can be seen from Table 2, the contributions of radon and its daughters to the annual dose rate account for a large proportion. Therefore, the determination of annual dose rate, radon escape or not, is indeed one of the key. Based on the radon movement in the soil, VSDesai et al. Arranged an experiment to determine radon in pottery and found that radon emissions were as high as 40% under soil drying conditions and in wet conditions due to radon dissolution, Scattered less. In addition, the emission of radon is also related to the type of pottery.