title: A new thoron atmosphere reference measurement system.
abstract: A new thoron reference ((220)Rn) in air measurement system is developed at the LNE-LNHB with the collaboration of the IRSN. This measurement system is based on a reference volume with an alpha detector which is able to directly measure thoron and its decay products at atmospheric pressure. In order to improve the spectrum quality of the thoron progenies, we have applied an electric field to catch the decay products on the detector surface. The developed system is a portative device which can be used to measure reference thoron atmosphere such as the BACCARA chamber at IRSN (Picolo et al., 1999). As this system also allows the measurement of radon ((222)Rn) in air, it was validated using the radon primary standards made at the LNE-LNHB. This thoron measurement system will be used, at IRSN, as a reference instrument in order to calibrate the thoron activity concentration in the BACCARA facility.
authors.affiliation: CEA, LIST, Laboratoire National Henri Becquerel (LNE-LNHB), Bât 602 PC111, CEA Saclay, 91191 Gif-Sur-Yvette, Cedex, France. Electronic address: benoit.sabot@cea.fr.
authors.forename: B
authors.initials: B
authors.lastname: Sabot
authors.affiliation: CEA, LIST, Laboratoire National Henri Becquerel (LNE-LNHB), Bât 602 PC111, CEA Saclay, 91191 Gif-Sur-Yvette, Cedex, France.
authors.forename: S
authors.initials: S
authors.lastname: Pierre
authors.affiliation: Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES, SCA, LPMA, Centre de Saclay, 91192 Gif-sur-Yvette, France.
authors.forename: N
authors.initials: N
authors.lastname: Michielsen
authors.affiliation: Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES, SCA, LPMA, Centre de Saclay, 91192 Gif-sur-Yvette, France.
authors.forename: S
authors.initials: S
authors.lastname: Bondiguel
authors.affiliation: CEA, LIST, Laboratoire National Henri Becquerel (LNE-LNHB), Bât 602 PC111, CEA Saclay, 91191 Gif-Sur-Yvette, Cedex, France.
authors.forename: P
authors.initials: P
authors.lastname: Cassette
keywords: Primary standard; Radon; Rn-220; Rn-222; Thoron