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Nuclear Data Gone Awry: Error in the IAEA Beam Monitor Reference Cross Section, <sup>nat</sup>Ni(d,x)<sup>61</sup>Cu, Discovered while Measuring a Discrepant <sup>40</sup>Ar(d,p)<sup>41</sup>Ar Reaction.

ORAL

Abstract

To investigate the use of argon as a deuteron beam stopping material, the 40Ar(d,p)41Ar cross section was measured at average deuteron energies of 3.6 MeV, 5.5 MeV, and 7.0 MeV using an activation method with nickel degraders. The natNi(d,x)61Cu reaction has historically been one of only a few IAEA-recommended deuteron beam monitor reactions. A discrepancy was observed between the accepted and measured values of the intensity ratio of the two strongest gamma rays following 61Cu β decay. This has significant impact to published cross sections measured in ratio to that beam monitor cross section. To determine the error's magnitude, over a hundred measurements of the 283 keV to 656 keV gamma-ray emission ratio were collected from seven experiments and a variety of detectors and geometries. A weighted average indicates an error in the value listed in the Nuclear Data Sheets of 11%. Following this correction, the 40Ar(d,p)41Ar cross section was determined from activation to be ~40% higher than a previous measurement and an order of magnitude higher than TENDL, further demonstrating the need for multiple, independent measurements of often-accepted nuclear data.

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Presenters

  • Darren L Bleuel

    Lawrence Livermore National Laboratory, Lawrence Livermore Natl Lab, Lawrence Livermore National Lab

Authors

  • Darren L Bleuel

    Lawrence Livermore National Laboratory, Lawrence Livermore Natl Lab, Lawrence Livermore National Lab

  • Scott G Anderson

    Lawrence Livermore Natl Lab

  • Lee A Bernstein

    Lawrence Berkeley National Laboratory, University of California, Berkeley

  • Josh A Brown

    University of California, Berkeley

  • Joseph A Caggiano

    Lawrence Livermore Natl Lab

  • Bethany L Goldblum

    Lawrence Berkeley National Laboratory

  • Joseph M Gordon

    University of California, Berkeley

  • James M Hall

    Lawrence Livermore Natl Lab

  • Keegan P Harrig

    U. C. Davis

  • Micah S Johnson

    Lawrence Livermore National Lab; San Jose State University, Lawrence Livermore Natl Lab

  • Thibault A Laplace

    University of California, Berkeley

  • Roark A Marsh

    Lawrence Livermore Natl Lab

  • Mairaid E Montague

    University of Tennessee, Knoxville

  • Jonathan T Morrell

    Lawrence Berkeley National Laboratory

  • Andrew Ratkiewicz

    Lawrence Livermore Natl Lab

  • Brian Rusnak

    Lawrence Livermore Natl Lab

  • Ray Souza

    Lawrence Livermore Natl Lab

  • Carol A Velsko

    Lawrence Livermore Natl Lab, Lawrence Livermore National Laboratory

  • Andrew S Voyles

    University of California, Berkeley