Choi V W Y, Ng C K M, Lam R K K, Janik M, Sorimachi A, Kranrod C, Nikezic D, Tokonami S, Yu K N
Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Kowloon, Hong Kong.
Radiat Prot Dosimetry. 2010 Oct;141(4):404-7. doi: 10.1093/rpd/ncq255. Epub 2010 Sep 10.
The 'proxy equilibrium factor' (F(p)) method has been developed for long-term determination of airborne radon progeny concentrations using LR 115 solid-state nuclear track detectors. In this paper, the effects of (220)Rn on the F(p) method have been studied. The correction to the track density was related to a parameter α which was the ratio of the sum of activity concentrations of alpha-particle emitting radionuclides in the (220)Rn decay chain to the activity concentration of (220)Rn alone. Under commonly encountered circumstances, α could not be smaller than 2. An attempt was made to verify this using the exposure chamber at the National Institute of Radiological Sciences (NIRS), Chiba, Japan. A most interesting observation of α < 2 for very high (220)Rn concentrations and very low equilibrium factors for (220)Rn in the exposure chambers was made. A possible explanation was the substantial deposition of (216)Po under the extreme conditions inside the exposure chambers.
“替代平衡因子”（F(p)）法已被开发出来，用于使用LR 115固态核径迹探测器长期测定空气中氡子体浓度。本文研究了(220)Rn对F(p)法的影响。径迹密度的校正与参数α有关，α是(220)Rn衰变链中发射α粒子的放射性核素活度浓度之和与单独的(220)Rn活度浓度之比。在通常遇到的情况下，α不能小于2。尝试在日本千叶市国立放射科学研究所（NIRS）的曝光室进行验证。在曝光室中观察到，对于非常高的(220)Rn浓度，α < 2，且(220)Rn的平衡因子非常低，这一现象非常有趣。一个可能的解释是曝光室内极端条件下(216)Po的大量沉积。
