Bias in the measurement of radon gas using ionization chambers: Application to SIR

Sylvie Pierre (1) , Benoît Sabot (1) , Philippe Cassette (1) , J. Liang (2) , S. Courte (3) , L. Ferreux (1) , G. Ratel (3)

1 LNHB (CEA, LIST) - Laboratoire National Henri Becquerel (CEA, LIST)
2 National Institute of Metrology [Beijing]
3 BIPM - Bureau International des Poids et Mesures

Two main non-destructive techniques can be used to measure standard Rn-222 gas ampoules: well-type ionization chambers and gamma-ray spectrometry, the former being used in the Systeme International de Reference (SIR) for international comparison purposes. The reliability of these techniques requires that the variability of the flame-sealed gas glass ampoules used have a negligible influence on the detector response. This variability is studied in this work by considering three parameters: the volume of the ampoule, the position of the sealing point and the thickness of the glass. Results showed that variability of the gas ampoules induced measurement bias larger than the uncertainty of the standard sources.

Mots clés: metrology; gas ampoule; Gamma spectrometry; Ionization chamber; SIR; 222Rn; gamma-rays; radioactivity; ionizing radiation; ionization chamber; spectrometry; reference source; Primary activity measurement

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

Sylvie Pierre, Benoît Sabot, Philippe Cassette, J. Liang, S. Courte, et al.. Bias in the measurement of radon gas using ionization chambers: Application to SIR. Applied Radiation and Isotopes, 2018, 134 (SI), pp.13-17. ⟨10.1016/j.apradiso.2017.10.040⟩. ⟨cea-01803823⟩