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Title: A kinematically complete, interdisciplinary, and co-institutional measurement of the 19F(α,n) cross section for nuclear safeguards science

Alpha particles emitted from the decay of uranium in a UF6 matrix can interact with fluorine and generate neutrons via the 19F(α,n)22Na reaction. These neutrons can be used to determine the uranium content in a UF6 storage cylinder. The accuracy of this self-interrogating, non-destructive assay (NDA) technique is, however, limited by the uncertainty of the 19F(α,n)22Na cross section. We have performed complementary measurements of the 19F(α,n)22Na reaction with both 4He and 19F beams to improve the precision of the 19F(α,n)22Na cross section over the alpha energy range that encompasses common actinide alpha decay needed for NDA studies. We have determined an absolute cross section for the 19F(α,n)22Na reaction to an average precision of 7.6% over the alpha energy range of 3.9 – 6.7 MeV. We utilized this cross section in a simulation of a 100 g spherical UF6 assembly and obtained a change in neutron emission rate values of approximately 10-12%, and a significant (factor of 3.6) decrease in the neutron emission rate uncertainty (from 50-51% to 13-14%), compared to simulations using the old cross section. Our new absolute cross section enables improved interpretations of NDAs of containers of arbitrary size and configuration.
Authors:
 [1] ;  [2] ;  [2] ;  [3] ;  [3] ;  [4] ;  [2] ;  [5] ;  [2] ;  [4] ;  [4] ;  [4] ;  [6] ;  [6] ;  [6] ;  [6] ;  [6] ;  [6] ;  [6] ;  [6] more »;  [6] ;  [6] ;  [6] ;  [6] ;  [6] ;  [7] ; ; ;  [7] ;  [6] ;  [6] ;  [6] ;  [8] ;  [9] ;  [3] « less
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. Idaho National Lab. (INL), Idaho Falls, ID (United States)
  4. Rutgers Univ., New Brunswick, NJ (United States)
  5. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Michigan, Ann Arbor, MI (United States)
  6. Univ. of Notre Dame, IN (United States)
  7. Univ. of Tennessee, Knoxville, TN (United States)
  8. Colorado School of Mines, Golden, CO (United States)
  9. Tennessee Technological Univ., Cookeville, TN (United States)
Publication Date:
OSTI Identifier:
1263500
Report Number(s):
INL/EXT--16-38791
TRN: US1601611
DOE Contract Number:
AC07-05ID14517
Resource Type:
Technical Report
Research Org:
Idaho National Lab. (INL), Idaho Falls, ID (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation (NA-20)
Contributing Orgs:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rutgers Univ., New Brunswick, NJ (United States); Univ. of Notre Dame, IN (United States); Univ. of Tennessee, Knoxville, TN (United States)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL PROTECTION; SODIUM 22; FLUORINE 19 TARGET; URANIUM HEXAFLUORIDE; ALPHA DECAY; MEV RANGE 01-10; NEUTRONS; NEUTRON EMISSION; SPHERES; EXCITATION FUNCTIONS; ACCURACY; URANIUM; ALPHA REACTIONS; SAFEGUARDS; COMPUTERIZED SIMULATION; GAS CYLINDERS; STORAGE; NUCLEAR REACTION ANALYSIS; COMPOUND-NUCLEUS REACTIONS F(alpha,n)