Simulation and analysis of list mode measurements on SILENE reactor

TL;DR

This paper presents a simulation and analysis framework for neutron list mode measurements on the SILENE reactor, combining MCNPX simulations with a custom postprocessing software to evaluate fissile system characteristics.

Contribution

It introduces a novel integrated approach for simulating and analyzing neutron list mode data using MCNPX and a custom postprocessor, enabling detailed fissile system characterization.

Findings

Successful simulation of neutron time correlation measurements

Development of a custom postprocessor for data analysis

Validation of simulation results against experimental data

Abstract

Neutron time correlation measurements are used to characterize fissile systems. For this purpose, detailed information are obtained using list mode measurements where the neutron detection times are recorded in a file called the time list file. In this article, we present the simulation and analysis of list mode measurements performed on SILENE reactor. Analogue Monte Carlo simulations are performed using MCNPX code and the synthetic time list file is obtained by processing the MCNPX-PTRAC coincidence capture file. Both measured and computed time list files are processed using the same postprocessor that we have developed. This software is used to calculate counting statistics data like counting number probability distribution, Rossi alpha and Feynman functions for time gates of increasing duration. The parameter uncertainties are evaluated using a block bootstrap method.