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.

*Performed under the auspices of the U.S. DOE by LLNL and LBNL under Contracts DE-AC52-07NA27344 and DE-AC02-05CH11231.

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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