Monte Carlo Simulation and measurement of Calibration Neutron Monitor count rate dependence on proximity to water

Abstract
Due to their global availability, neutron monitors play a crucial role in measuring time variations in the Galactic cosmic ray flux. A portable calibration neutron monitor (CalMon) is useful for intercalibrating various neutron monitors to ensure accurate measurements. A common technique to ensure that the calibration is done in a consistent environment is to place the CalMon at some height above a wide container (such as a portable swimming pool) filled with water. This study investigates the impact of CalMon height and water depth on the count rate ratio relative to a standard 18NM64 count rate recorded nearby (CalMon/18NM64). We compare simulated data from the FLUKA Monte Carlo package to experimental data from [1] to demonstrate the statistical accuracy of our simulation. Using the simulation results, we then extend the study of the proximity-to-water effect on the counting rate. In this work, we present a preliminary empirical model by analyzing the CalMon/18NM64 as a function of CalMon to water distance. Overall, our study enhances understanding of the response of calibration monitors (now often called "mini-neutron monitors") operated in various locations worldwide, and validates the Monte Carlo techniques used to model the response of the global neutron monitor network.
Description
This article was originally published in Journal of Physics: Conference Series. The version of record is available at: https://doi.org/10.1088/1742-6596/2653/1/012018
Keywords
Citation
Duangjai, B, W Nuntiyakul, A Seripienlert, A Pagwhan, K Chaiwongkhot, A Sáiz, D Ruffolo, and P Evenson. “Monte Carlo Simulation and Measurement of Calibration Neutron Monitor Count Rate Dependence on Proximity to Water.” Journal of Physics: Conference Series 2653, no. 1 (December 1, 2023): 012018. https://doi.org/10.1088/1742-6596/2653/1/012018.