10:30 AM - 10:45 AM
[3H03] Theoretical Derivation of Feynman-α Method based on Photon-Neutron Coupling Probability Generating Function Equations
Keywords:prompt neutron decay constant, gamma-ray, reactor noise, probability generating function, Feynman-α method, PHITS
To discuss whether the prompt neutron decay constant α can be estimated from measured time-series data of gamma-ray counts, we derived the theoretical formula of Feynman-α method based on the neutron-photon coupling probability generating function (PGF) equations. As a result, it is confirmed that the conventional theoretical formula should be modified by adding the constant background component because the detected gamma-rays have additional correlation due to the multiplicities of photon-sources and the photo-atomic reactions. By fitting the derived theoretical formula to virtual reactor noise data (time-series data of Compton scattering counts) using the PHITS code, we try estimating the prompt neutron decay constant.