title: Set-up of a new TDCR counter at IRA-METAS.
abstract: A triple-to-double coincidence ratio (TDCR) counter was recently constructed at IRA-METAS for liquid scintillation based primary activity standardisations. A description of its optical chamber, efficiency change tools, photomultiplier tubes (PMTs) and electronics is given. This TDCR system was validated by measuring several standard solutions of beta emitters including (45)Ca, (14)C, (63)Ni and (3)H. The activity concentrations, obtained from these measurements and efficiencies computed with a FORTRAN code we developed for symmetric and asymmetric PMTs, agree with the certified values within uncertainties.
authors.affiliation: Institut de Radiophysique, Lausanne, Switzerland. Electronic address: youcef.nedjadi@chuv.ch.
authors.forename: Youcef
authors.initials: Y
authors.lastname: Nedjadi
authors.affiliation: Institut de Radiophysique, Lausanne, Switzerland.
authors.forename: Claude
authors.initials: C
authors.lastname: Bailat
authors.affiliation: Institut de Radiophysique, Lausanne, Switzerland.
authors.forename: Yvan
authors.initials: Y
authors.lastname: Caffari
authors.affiliation: Laboratoire National Henri Becquerel, Gif sur Yvette Cedex, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Cassette
authors.affiliation: Institut de Radiophysique, Lausanne, Switzerland.
authors.forename: François
authors.initials: F
authors.lastname: Bochud
keywords: (14)C; (3)H; (45)Ca; (63)Ni; Activity standardisation; Liquid scintillation; TDCR