Semi-continuous measurement of the unattached radon decay products size distributions from 0.5 to 5nm by an array of annular diffusion channels
Autor: | G. Tymen, N. Michielsen |
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Přispěvatelé: | Laboratoire de Physique et de Métrologie des Aérosols (DSU/SERAC/LPMA), Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Université européenne de Bretagne - European University of Brittany (UEB) |
Rok vydání: | 2007 |
Předmět: |
Inverse problems
Radon decay products radon isotope Atmospheric Science geometry Environmental Engineering Materials science radioisotope decay 010504 meteorology & atmospheric sciences aerosol Particle size analysis Inverse transform sampling chemistry.chemical_element Radon 010501 environmental sciences 01 natural sciences Diffusion size distribution measurement method Sampling radiation monitor 0105 earth and related environmental sciences particulate matter [PHYS]Physics [physics] Fluid Flow and Transfer Processes environmental radioactivity algorithm EVE algorithm Mechanical Engineering Detector article radon 222 radon particle size Inverse problem Pollution Aerosol Computational physics Annular diffusion channels priority journal chemistry Diffusion batteries Unattached fraction Particle-size distribution Nanoparticles radon 222 daughter Particle size Deconvolution radiation monitoring |
Zdroj: | Journal of Aerosol Science Journal of Aerosol Science, 2007, 38 (11), pp.1129-1139. ⟨10.1016/j.jaerosci.2007.08.008⟩ |
ISSN: | 0021-8502 |
Popis: | A new diffusion battery was designed to make precise measurements of the indoor activity size distribution of short-lived 222Rn decay products in the size range of 0.5-5 nm. It relies on the selection of particles by five annular diffusion channels (ADCs) and on the use of a non-linear inversion method, EVE, for the reconstruction of the particle size distributions. The ADC geometry proved to allow a better selection of the particles size compared to the wire screen and the implementation of an alpha detector set in front of the sampling filter for semi-continuous activity measurements. EVE algorithm was chosen in order to take into account the uncertainties of the measurement in the deconvolution process. The diffusion battery was tested in a radon chamber, and results showed a good reproducibility of the measurements. The degree of confidence on the obtained size distributions is then discussed. Results show that the relative uncertainty on the penetration data has to be less than 10% in order to obtain a reliable size distribution. © 2007 Elsevier Ltd. All rights reserved. |
Databáze: | OpenAIRE |
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