Author:
Karunakara N.,Shetty Trilochana,Sahoo B. K.,Kumara K. Sudeep,Sapra B. K.,Mayya Y. S.
Abstract
AbstractThe paper describes a novel technique to harvest 222Rn laden air from soil gas of natural origin as a highly efficient source of 222Rn for calibration applications in a walk-in type 222Rn calibration chamber. The technique makes use of a soil probe of about 1 m to draw soil gas, through a dehumidifier and a delay volume, using an air pump to fill the calibration chamber. 222Rn concentration in the range of a few hundred Bq m−3 to a few tens of kBq m−3 was easily attained in the chamber of volume 22.7 m3 within a short pumping duration of 1 h. A new technique referred to as “semi-dynamic mode of operation” in which soil gas is injected into the calibration chamber at regular intervals to compensate for the loss of 222Rn due to decay and leak is discussed. Harvesting soil gas has many important advantages over the traditional methods of 222Rn generation for calibration experiments using finite sources such as solid flow-through, powdered emanation, and liquid sources. They are: (1) soil gas serves as an instantaneous natural source of 222Rn, very convenient to use unlike the high strength 226Ra sources used in the calibration laboratories, and has no radiation safety issues, (2) does not require licensing from the regulatory authority, and (3) it can be used continuously as a non-depleting reservoir of 222Rn, unlike other finite sources. The newly developed technique would eliminate the need for expensive radioactive sources and thereby offers immense application in a variety of day to day experiments—both in students and research laboratories.
Funder
Board of Research in Nuclear Sciences
Publisher
Springer Science and Business Media LLC
Reference46 articles.
1. Trilochana, S. et al. A walk-in type 222Rn chamber for calibration of radon and progeny measuring devices and inter-comparison measurements. Radiat. Prot. Dosim. 187, 1–16 (2019).
2. Yamada, Y. et al. Performance of radon/aerosol chamber at NIRS, Japan. Preprint at https://www.ipen.br/biblioteca/cd/irpa/2004/files/6a70.pdf (2001).
3. Liang, J. C. et al. Development of calibration facility for 222Rn and its progenies at NIM (CHINA). Radiat. Prot. Dosim. 167, 82–86 (2015).
4. Jong, M. L., Kil, H. A., Ha, S. C. & Tae, S. P. Development of radon calibration chamber at KRISS. Appl. Radiat. Isot. 61, 237–241 (2004).
5. Sahoo, B. K., Sapra, B. K., Kanse, S. D., Gaware, J. J. & Mayya, Y. S. A new pin-hole discriminated 222Rn/220Rn passive measurement device with single entry face. Radiat. Meas. 58, 52–60 (2013).
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