Effects of the Two-Fission-Neutron Distributions in Reactivity Measurements with the 252Cf Source

  • Felix C. Difilippo
Conference paper
Part of the Research Reports in Physics book series (RESREPORTS)


Stochastic descriptors based on the first and second moments of the probability distribution of the neutrons in phase space \( \bar{\mu }{\mkern 1mu} {\mkern 1mu} = {\mkern 1mu} {\mkern 1mu} \left( {\bar{r},{\mkern 1mu} \bar{v}} \right) \) are extensively used in the nuclear industry for the non-intrusive measurement of nuclear parameters. One of these methods is based on the 252Cf source which has been used in an unprecedented range of situations and reactivities; the interpretation of this method is sensitive to the distribution of two neutrons coming from the same fission, \( \gamma \left( {\bar{v},{\mkern 1mu} \bar{v}'} \right) \). The few direct measurements of this nn correlation have shown that γ depends on \( \cos \theta '' = \bar{v}.\bar{v}'|vv' \) and the neutron energies, the available experimental data was used to quantify the sensitivity of the 252Cf method to the anisotropies of the nn correlation. It was found that it affects the interpretation of the reactivity measurement for low values of the multiplication constant.


Neutron Source Neutron Energy Angular Correlation Average Importance Reactivity Measurement 
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Copyright information

© Springer-Verlag Berlin Heidelberg 1992

Authors and Affiliations

  • Felix C. Difilippo
    • 1
  1. 1.Oak Ridge National LaboratoryOak RidgeUSA

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