Monte Carlo calculations of LR115 detector response to {sup 222}Rn in the presence of {sup 220}Rn

Journal Article · Sat Apr 01 04:00:00 EST 2000 · Health Physics

DOI:https://doi.org/10.1097/00004032-200004000-00005· OSTI ID:20020646

Nikezic, D; Yu, K N

The sensitivities (in m) of bare LR115 detectors and detectors in diffusion chambers to {sup 222}Rn and {sup 220}Rn chains are calculated by the Monte Carlo method. The partial sensitivities of bare detectors to the {sup 222}Rn chain are larger than those to the {sup 220}Rn chain, which is due to the higher energies of alpha particles in the {sup 220}Rn chain and the upper energy limit for detection for the LR115 detector. However, the total sensitivities are approximately equal because {sup 220}Rn is always in equilibrium with its first progeny, which is not the case for the {sup 222}Rn chain. The total sensitivity of bare LR115 detectors to {sup 222}Rn chain depends linearly on the equilibrium factor. The overestimation in {sup 222}Rn measurements with bare detectors caused by {sup 220}Rn in air can reach 10% in normal environmental conditions. An analytical relationship between the equilibrium factor and the ratio between track densities on the bare detector and the detector enclosed in chamber is given in the last part of the paper. This ratio is also affected by {sup 220}Rn, which can disturb the determination of the equilibrium factor.

• Research Organization: City Univ. of Hong Kong, Kowloon (HK)
• OSTI ID: 20020646
• Journal Information: Health Physics, Journal Name: Health Physics Journal Issue: 4 Vol. 78; ISSN HLTPAO; ISSN 0017-9078
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
54 ENVIRONMENTAL SCIENCES
MONTE CARLO METHOD
PERFORMANCE
RADIATION DETECTORS
RADIATION MONITORING
RADON 220
RADON 222
SENSITIVITY ANALYSIS