Applicability of Dynamic Mode Decomposition to Estimate Fundamental Mode Component of Prompt Neutron Decay Constant from Experimental Data

Abstract

To robustly estimate the fundamental mode component of prompt neutron decay constant α in a subcritical system, dynamic mode decomposition (DMD) is applied to time-series data obtained by the pulsed-neutron source (PNS) and Rossi-α methods. For the statistical uncertainty quantification of α by DMD, randomly sampled virtual data are used for the DMD procedure. The applicability of DMD is demonstrated by analyzing the experimental results by the PNS and Rossi-α methods, which are performed at the Kyoto University Critical Assembly (KUCA). When applying the DMD to the PNS and Rossi-α experimental data, a constant signal was added to the experimental data to remove the background constant component. The application results indicate that DMD enables one to robustly estimate the fundamental mode component of α in the PNS and Rossi-α methods.

Keywords:

• Prompt neutron decay constant
• dynamic mode decomposition
• fundamental mode component
• pulsed-neutron source method
• Rossi-α method

Acknowledgments

This study has been carried out under the visiting researcher’s program at the Kyoto University Institute for Integrated Radiation and Nuclear Science. This study was supported by the Japan Society for the Promotion of Science Grant-in-Aid for Scientific Research (C) (grant number 19K05328).