https://doi.org/10.1051/epjconf/202124709024
USING PROMPT NEUTRON DECAY CONSTANT MEASUREMENTS TO OBTAIN ADDITIONAL KINETICS INFORMATION
Los Alamos National Laboratory PO Box 1663 Los Alamos, NM 87545
gmckenzie@lanl.gov
tgrove@lanl.gov
jesson@lanl.gov
Published online: 22 February 2021
Prompt neutron decay constant measurements are typically used to infer the prompt neutron lifetime in a chain-reacting system, but these measurements include much more information about the kinetics of the system. This work focuses specifically on the Rossi-α method of measuring the prompt neutron decay constant. The Rossi-α system of equations consists of five unknown parameters. With five unknowns and three equations, the system of equations solved by the Rossi-α measurement is under-determined. It has been postulated that a well posed problem can be formulated using independent measurement configurations on a single system. The external source strength, the effective delayed neutron fractions, and Diven’s parameter do not typically change for different configurations of a single experiment. If good detector geometry is chosen, the detector efficiency does not change for multiple measurements of a single experiment using Rossi-α measurements. By making these assumptions, there are only two unique variables. This knowledge can be used to solve for most of the unique parameters using two independent, unique Rossi-α measurements.
Key words: neutron noise / prompt neutron decay constants / kinetics parameters / Rossi-α
© The Authors, published by EDP Sciences, 2021
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
