title: Long-term determination of airborne radon progeny concentrations using LR 115 detectors and the effects of thoron.
abstract: 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.
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Kowloon, Hong Kong.
authors.forename: V W Y
authors.initials: VW
authors.lastname: Choi
authors.forename: C K M
authors.initials: CK
authors.lastname: Ng
authors.forename: R K K
authors.initials: RK
authors.lastname: Lam
authors.forename: M
authors.initials: M
authors.lastname: Janik
authors.forename: A
authors.initials: A
authors.lastname: Sorimachi
authors.forename: C
authors.initials: C
authors.lastname: Kranrod
authors.forename: D
authors.initials: D
authors.lastname: Nikezic
authors.forename: S
authors.initials: S
authors.lastname: Tokonami
authors.forename: K N
authors.initials: KN
authors.lastname: Yu
mesh_terms: D000396:Air Pollutants, Radioactive; D016902:Air Pollution, Indoor / Q000032:analysis*; D000465:Algorithms; D000512:Alpha Particles; D004781:Environmental Exposure; D005740:Gases; D006798:Housing; D007564:Japan; D015233:Models, Statistical; D011059:Polonium / Q000032:analysis; D011834:Radiation Monitoring / Q000295:instrumentation*; D011874:Radiometry; D011886:Radon / Q000032:analysis*; D017687:Radon Daughters / Q000032:analysis*; D012306:Risk
chemical_list: D000396:Air Pollutants, Radioactive; D005740:Gases; D017687:Radon Daughters; D011059:Polonium; D011886:Radon