Characterization of Neutron Emission Rates of Commercial ²⁵²Cf Sources

Technical Report · Wed Oct 01 00:00:00 EDT 2025

DOI:https://doi.org/10.2172/3018377· OSTI ID:3018377

Burggraf, Jeffrey Smith ^[1]; Chichester, David L. ^[1]

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1. Idaho National Laboratory (INL), Idaho Falls, ID (United States)

Accurate knowledge of ²⁵²Cf neutron emission rates is critical for modeling and fast-neutron experiments, yet commercial sources are often supplied without traceable calibration or uncertainty estimates. This report describes a method to characterize ²⁵²Cf sources using a pulse-shape-discrimination (PSD) scintillator. The scintillator was efficiency-calibrated against a time-tagged ²⁵²Cf fission chamber manufactured at ORNL over 40 years ago. Isotopic evolution of the calibration source was modeled using Bateman equations to account for changes in the effective average neutrons per fission at the time of measurement. The calibrated scintillator was then used to measure absolute emission rates of several commercial ²⁵²Cf sources, revealing deviations of up to 12% from nominal manufacturer values. This methodology provides a practical approach for establishing uncertainty-quantified ²⁵²Cf neutron emission rates, improving fidelity in simulations and supporting the accurate interpretation of measurements.

• Research Organization: Idaho National Laboratory (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE); USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: AC07-05ID14517
• OSTI ID: 3018377
• Report Number(s): INL/RPT--25-88190
• Country of Publication: United States
• Language: English

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46 - INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
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