title: Experimental re-evaluation of the γ-ray energy and emission probability for the 159 keV transition in 238U following the α-decay of 242Pu.
abstract: Because of the very low specific activity of (242)Pu, the non-destructive assay of this isotope by means of conventional high-resolution gamma-spectrometry (HRGS) is possible only for Pu samples highly rich in (242)Pu. For bulk samples suffering from the gamma self-attenuation and self-fluorescence effects, the only practical choice for the quantitative analysis of (242)Pu is the weak γ-line emitted in the 159 keV transition of its α-decay daughter (238)U. A recent study revealed a significant disagreement between the (242)Pu mass values in a 99.72% enriched (242)PuO(2) sample as reported by HRGS and neutron coincidence counting. This fact motivated the present study on the experimental re-evaluation of the γ-emission probability for the 159 keV transition using a combination of α-, γ- and mass-spectrometry techniques. The obtained new emission probability P(2)=(2.20±0.08)10(-6) turned out to be ≈35% smaller than the currently adopted value. The study also suggested a new value E(2)=159.018±0.016 keV for the energy of the respective γ-ray.
authors.affiliation: European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe, Germany. berlizov@kinr.kiev.ua
authors.forename: A N
authors.initials: AN
authors.lastname: Berlizov
authors.forename: P
authors.initials: P
authors.lastname: van Belle
authors.forename: E
authors.initials: E
authors.lastname: Zuleger
authors.forename: H
authors.initials: H
authors.lastname: Ottmar
mesh_terms: D000512:Alpha Particles; D005720:Gamma Rays; D011005:Plutonium / Q000032:analysis / Q000737:chemistry*; D011336:Probability; D011850:Radioactive Waste / Q000032:analysis; D013051:Spectrometry, Gamma / Q000379:methods; D014501:Uranium / Q000032:analysis
chemical_list: D011850:Radioactive Waste; D014501:Uranium; D011005:Plutonium