Impact of Wind Speed on Response of Diffusion-Type Radon-Thoron Detectors to Thoron
Abstract
1. Introduction
2. Materials and Methods
2.1. Detectors
2.2. Experiment
2.3. Analysis
3. Results
4. Discussion
5. Conclusions
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
Abbreviations
A | Area of the air inlet(s) of the detector (RADUETs or AlphaGUARD) |
Cbg | Concentration indicated by AlphaGUARD before starting exposure to thoron |
Cex | Concentration indicated by AlphaGUARD during exposure to thoron |
CTn, in | Thoron concentration in diffusion chamber of the detector (RADUETs or AlphaGUARD) |
CTn, out | Thoron concentration in a thoron calibration chamber |
d | Thickness of a porous medium (filter or sponge) |
Dp | Diffusion coefficient in a porous medium (filter or sponge) |
Nbg | Background track density on CR-39 |
Nex | Track density on CR-39 formed after exposure of RADUETs to thoron is completed |
RA | Responses to thoron for AlphaGUARD |
RR | Responses to thoron for RADUETs |
t | Time |
T | Time for exposure of RADUETs to thoron |
u | Air velocity induced by pressure gradient in a porous medium |
V | Volume of the detector (RADUETs or AlphaGUARD) |
γ | Air exchange rate of the detector (RADUETs or AlphaGUARD) |
λ | Decay constant of thoron |
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Rotational Speed Level | Wind Speed (m s−1) | ||
---|---|---|---|
Center 1 | Near Wall 1 | Average 2 | |
Very low | 0.33 ± 0.01 | 0.20 ± 0.02 | 0.27 |
Low | 0.75 ± 0.02 | 0.44 ± 0.03 | 0.59 |
Reference | 0.85 ± 0.05 | 0.85 ± 0.05 | 0.85 |
High | 1.84 ± 0.05 | 2.00 ± 0.06 | 1.92 |
RADUETs | |||||
Wind Speed (m s−1) | Exposure Time (T, h) | Time-Integrated Thoron Concentration (CTn, out × T, kBq m−3 h) | Net Track Density (Nex–Nbg, tracks mm−2) 1 | Response to Thoron (RR, tracks mm−2 (kBq m−3 h)−1) | |
0.27 | 71 | 1082 | 12.6 ± 1.3 | 0.012 ± 0.001 | |
0.59 | 82 | 1281 | 24.6 ± 1.8 | 0.019 ± 0.001 | |
0.85 | 72 | 1016 | 19.7 ± 0.5 | 0.019 ± 0.001 | |
1.92 | 87 | 1007 | 24.0 ± 0.7 | 0.024 ± 0.001 | |
AlphaGUARD | |||||
Wind Speed (m s−1) | Exposure Time (T, h) | Thoron Concentration (CTn, out, Bq m−3) 2 | AlphaGUARD Value (Bq m−3) 2 | Response to Thoron (RA) | |
Cex | Cbg | ||||
0.27 | 21 | 12752 ± 359 | 549 ± 42 | 11 ± 3 | 0.042 ± 0.004 |
0.59 | 17 | 12294 ± 323 | 816 ± 37 | 11 ± 3 | 0.065 ± 0.003 |
0.85 | 16 | 932 ± 80 | 98 ± 12 | 4 ± 2 | 0.101 ± 0.016 |
0.85 | 17 | 1049 ± 65 | 89 ± 9 | 8 ± 3 | 0.078 ± 0.011 |
0.85 | 20 | 12254 ± 680 | 900 ± 50 | 11 ± 3 | 0.073 ± 0.006 |
1.92 | 12 | 1165 ± 76 | 115 ± 13 | 9 ± 3 | 0.091 ± 0.013 |
1.92 | 15 | 1014 ± 117 | 94 ± 9 | 10 ± 3 | 0.083 ± 0.013 |
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Omori, Y.; Tamakuma, Y.; Nugraha, E.D.; Suzuki, T.; Saputra, M.A.; Hosoda, M.; Tokonami, S. Impact of Wind Speed on Response of Diffusion-Type Radon-Thoron Detectors to Thoron. Int. J. Environ. Res. Public Health 2020, 17, 3178. https://doi.org/10.3390/ijerph17093178
Omori Y, Tamakuma Y, Nugraha ED, Suzuki T, Saputra MA, Hosoda M, Tokonami S. Impact of Wind Speed on Response of Diffusion-Type Radon-Thoron Detectors to Thoron. International Journal of Environmental Research and Public Health. 2020; 17(9):3178. https://doi.org/10.3390/ijerph17093178
Chicago/Turabian StyleOmori, Yasutaka, Yuki Tamakuma, Eka Djatnika Nugraha, Takahito Suzuki, Miki Arian Saputra, Masahiro Hosoda, and Shinji Tokonami. 2020. "Impact of Wind Speed on Response of Diffusion-Type Radon-Thoron Detectors to Thoron" International Journal of Environmental Research and Public Health 17, no. 9: 3178. https://doi.org/10.3390/ijerph17093178
APA StyleOmori, Y., Tamakuma, Y., Nugraha, E. D., Suzuki, T., Saputra, M. A., Hosoda, M., & Tokonami, S. (2020). Impact of Wind Speed on Response of Diffusion-Type Radon-Thoron Detectors to Thoron. International Journal of Environmental Research and Public Health, 17(9), 3178. https://doi.org/10.3390/ijerph17093178