title: The effect of impurities on calculated activity in the triple-to-double coincidence ratio liquid scintillation method.
abstract: In the triple-to-double coincidence ratio (TDCR) method of liquid scintillation counting, unaccounted or improperly accounted impurities can result in lower-than-expected or higher-than-expected recovered activities, depending on the counting efficiency of the nuclide of interest, the counting efficiency of the radionuclidic impurity, and the amount of impurity present. We describe these general dependences using a simple model. The trends predicted by the model are tested experimentally using a series of mixed (241)Am/(3)H and (63)Ni/(3)H sources. An "impurity surface" is derived to facilitate an intuitive grasp of impurity phenomena in TDCR.
authors.affiliation: Physical Measurements Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899-8462, USA. denis.bergeron@nist.gov
authors.forename: Denis E
authors.initials: DE
authors.lastname: Bergeron
authors.forename: Ryan P
authors.initials: RP
authors.lastname: Fitzgerald
authors.forename: Brian E
authors.initials: BE
authors.lastname: Zimmerman
authors.forename: Jeffrey T
authors.initials: JT
authors.lastname: Cessna
mesh_terms: D016477:Artifacts; D045424:Complex Mixtures / Q000032:analysis*; D003198:Computer Simulation; D008956:Models, Chemical; D011829:Radiation Dosage; D011868:Radioisotopes / Q000032:analysis*; D012588:Scintillation Counting / Q000379:methods*
chemical_list: D045424:Complex Mixtures; D011868:Radioisotopes