title: Development of a low-level39Ar calibration standard - Analysis by absolute gas counting measurements augmented with simulation.
abstract: This paper describes the generation of39Ar, via reactor irradiation of potassium carbonate, followed by quantitative analysis (length-compensated proportional counting) to yield two calibration standards that are respectively 50 and 3 times atmospheric background levels. Measurements were performed in Pacific Northwest National Laboratory's shallow underground counting laboratory studying the effect of gas density on beta-transport; these results are compared with simulation. The total expanded uncertainty of the specific activity for the ~50×39Ar in P10 standard is 3.6% (k=2).
authors.affiliation: Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, USA. Electronic address: Richard.Williams@pnnl.gov.
authors.forename: R M
authors.initials: RM
authors.lastname: Williams
authors.affiliation: Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, USA.
authors.forename: C E
authors.initials: CE
authors.lastname: Aalseth
authors.affiliation: Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Brandenberger
authors.affiliation: Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, USA.
authors.forename: A R
authors.initials: AR
authors.lastname: Day
authors.affiliation: Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, USA.
authors.forename: E
authors.initials: E
authors.lastname: Finn
authors.affiliation: Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, USA.
authors.forename: E S
authors.initials: ES
authors.lastname: Fuller
authors.affiliation: Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, USA.
authors.forename: E W
authors.initials: EW
authors.lastname: Hoppe
authors.affiliation: Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, USA.
authors.forename: P H
authors.initials: PH
authors.lastname: Humble
authors.affiliation: Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Keillor
authors.affiliation: Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, USA.
authors.forename: E K
authors.initials: EK
authors.lastname: Mace
authors.affiliation: Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, USA.
authors.forename: A W
authors.initials: AW
authors.lastname: Myers
authors.affiliation: Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, USA.
authors.forename: C T
authors.initials: CT
authors.lastname: Overman
authors.affiliation: Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Panisko
authors.affiliation: Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, USA.
authors.forename: A
authors.initials: A
authors.lastname: Seifert
authors.affiliation: Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, USA.
authors.forename: S K
authors.initials: SK
authors.lastname: White
keywords: Absolute radiation measurement; Electroformed copper; Length compensated proportional counting; Ultra-low background; Uncertainty Analysis