Speaker
Description
Neutron monitors are crucial ground-based instruments for studying cosmic rays, requiring precise response function modeling to properly interpret flux variations. A new boron trifluoride (BF₃) proportional counter tube from LND Inc. maintains the identical geometry, gas volume, and pressure of the BP28 counter, a standard in NM64 neutron monitors, while differing in anode wire and cathode thickness. The Princess Sirindhorn Neutron Monitor (PSNM) in Chiang Mai, Thailand, operates 18NM64 tubes along with three bare BP28 tubes, one of which was relocated in 2018 to the ship-borne neutron monitor “Changvan” for Antarctic expeditions. In 2022–2023, a BF₃ tube from LND Inc. temporarily replaced one bare BP28 tube at PSNM, enabling a direct response comparison. We perform Monte Carlo simulations of secondary particle interactions in these tubes, incorporating monthly solar modulation parameters from Usoskin et al. (2017) to refine secondary particle flux predictions, and we benchmark against observed count rates from September 15, 2022, to October 5, 2023. This research was supported by the CMU Proactive Researcher Program, Chiang Mai University, the Development and Promotion of Science and Technology Talents Project (DPST), the National Science and Technology Development Agency (NSTDA), and National Research Council (NRCT): High-Potential Research Team Grant Program (N42A650868).
