Nuntiyakul W.Promfu T.Seripienlert A.Khamphakdee S.Pagwhan A.Sohn J.Oh S.Evenson P.Ruffolo D.Saiz A.Komonjinda S.Mahidol University2026-02-082026-02-082025-12-30Proceedings of Science Vol.501 (2025)https://repository.li.mahidol.ac.th/handle/123456789/114883A latitude survey was conducted in 2023–24 using the Changvan neutron monitor aboard the South Korean icebreaker “Araon” to investigate cosmic ray modulation over a broad range of geomagnetic cutoff rigidities. The semi-leaded configuration, comprising both leaded and unleaded proportional counters, enabled the extraction of empirical response functions for each tube. Fits to the Dorman function revealed shielding-dependent differences in rigidity sensitivity, including variations in spectral slope and cutoff sharpness. The results demonstrate the viability of compact neutron monitors for characterizing cosmic ray responses under varying geomagnetic and modulation conditions.MultidisciplinaryConference PaperSCOPUS10.22323/1.501.13482-s2.0-10502906660718248039