Correlation Measurements with {sup 252}Cf to Characterize Fissile Material

Technical Report · Tue Jan 04 04:00:00 EST 2000

DOI:https://doi.org/10.2172/816191· OSTI ID:816191

Mattingly, J K ^[1]

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1. ORNL

Measurements using {sup 252}Cf as a timed source of neutrons and gammas have in recent years undergone significant maturation. These methods use {sup 252}Cf as an observable source of spontaneous fission neutrons and gammas in conjunction with one or more neutron- and/or gamma-sensitive detectors to measure the time-distribution of correlated detector counts following (a) an observed {sup 252}Cf-fission event and/or (b) a counting event in another detector. Detection of {sup 252}Cf spontaneous fission is frequently achieved via use of a small ionization chamber in which the {sup 252}Cf is contained--in this case the timing of source emission events is random. However, one application subsequently described uses a neutron-absorbent ''shutter'' to modulate {sup 252}Cf emissions to produce a neutron source with deterministic timing. Other applications, frequently termed noise-analysis measurements, transform the time-distributions to the frequency domain. Collectively, these correlation methods use {sup 252}Cf to ''excite'' the fissile material and the response of the material is measured by an array of detectors and analyzed using standard time-correlation and/or frequency-analysis techniques. In recent years numerous advances have been made in the application of these methods to in-situ, or field measurements directed at characterizing various configurations of fissile material in operational facilities.

• Research Organization: ORNL Oak Ridge National Laboratory (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 816191
• Report Number(s): ORNL/TM-2000/3
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
DETECTION
FISSILE MATERIALS
FREQUENCY ANALYSIS
IONIZATION CHAMBERS
NEUTRON SOURCES
NEUTRONS
SPONTANEOUS FISSION