CHASM (CHerenkov Air SHower Model) Applied to EAS Reconstruction

CHASM (CHerenkov Air Shower Model) is a framework for the simulation of EAS (Extensive Air Shower) Cherenkov signals which leverages the universality of EAS charged particle distributions. CHASM runs in seconds, whereas existing EAS simulation frameworks like CORSIKA can take hours, especially for large showers. In this work, we show how CHASM was interfaced with a full detector simulation of the NICHE (Non Imaging CHErenkov) detectors at the Telescope Array Middle Drum site. Since CHASM can run quickly, the running of iterative simulations with varied parameters becomes feasible. Thus, the full simulation, from shower parameters to recorded raw data, was used as the model in a gradient descent minimizer to calculate the optimal shower parameters.