Count-loss effect in subcriticality measurement by pulsed neutron source method, (I) investigation on count-loss effect in determination of neutron decay constant

Abstract

The count-loss effect in determination of neutron decay constant by pulsed neutron source method was investigated. It was found that overestimation of neutron decay constant due to count-loss effect is seen while underestimation appears superiorly as the intensity of pulsed neutron source is getting higher. It was further demonstrated that the well-known count-loss correction procedures are not effective for overestimation although they suppress underestimation. Therefore, the pulsed neutron source method should be modified so as to have robustness against the count-loss effect.

Keywords:

• pulsed neutron source method
• count-loss effect
• neutron decay constant
• subcriticality
• measurement
• nuclear criticality safety

Acknowledgements

The authors would like to express their thanks to Dr Teruhiko Kugo for his valuable comments.