Study on the Impact of the Geomagnetic Field on IACT Array Performance

The Large High Altitude Air Shower Observatory (LHAASO) has discovered over 40 ultra-high-energy gamma-ray sources with energies exceeding 100 TeV, ushering in a new era for ultra-high-energy gamma-ray astronomy. To better understand the fine structure of gamma-ray emissions from these sources, the team proposed the Large Array of imaging atmospheric Cherenkov Telescopes (LACT) experiment, which includes 32 Cherenkov telescopes. This project, funded by Sichuan Province, is currently under construction, with the first telescope scheduled to be completed in 2025. Based on previous preliminary studies, the final array layout of LACT has been determined. To better evaluate the performance of the entire array configuration, simulations were conducted to investigate the performance variation of the layout across different azimuthal angles. The current simulation framework still relies on the combination of CORSIKA and sim_telarray, while event reconstruction is performed using a scheme based on Hillas parameters and stereoscopic reconstruction methods. The results of this study can help improve reconstruction accuracy and provide useful guidance for subsequent gamma-ray analyses.