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Title: Gamma Ray Mirrors for Direct Measurement of Spent Nuclear Fuel

Direct measurement of the amount of Pu and U in spent nuclear fuel represents a challenge for the safeguards community. Ideally, the characteristic gamma-ray emission lines from different isotopes provide an observable suitable for this task. However, these lines are generally lost in the fierce flux of radiation emitted by the fuel. The rates are so high that detector dead times limit measurements to only very small solid angles of the fuel. Only through the use of carefully designed view ports and long dwell times are such measurements possible. Recent advances in multilayer grazing-incidence gamma-ray optics provide one possible means of overcoming this difficulty. With a proper optical and coating design, such optics can serve as a notch filter, passing only narrow regions of the overall spectrum to a fully shielded detector that does not view the spent fuel directly. We report on the design of a mirror system and a number of experimental measurements.
 [1] ;  [2] ;  [2] ;  [1]
  1. Lawrence Livermore National Laboratory (LLNL)
  2. ORNL
Publication Date:
OSTI Identifier:
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment; Journal Volume: 743; Journal Issue: 1
Research Org:
Oak Ridge National Laboratory (ORNL)
Sponsoring Org:
NNSA USDOE - National Nuclear Security Administration (NNSA)
Country of Publication:
United States
multilayer mirrors; spent nuclear fuel; nondestructive assay