Method of estimating the EAS cores of Monte Carlo showers for the GRAPES-3 experiment

Abstract

Procedure of estimating the different extensive air shower (EAS) parameters is inherently linked to the accurate estimation of the cosmic-ray EAS cores. In EAS data analyses, the core of an EAS is estimated simultaneously with other crucial EAS parameters like shower size, shower age, etc. by fitting the lateral density data (LDD) of either the EAS charged secondaries or purely electrons with some suitably chosen lateral density function employing the maximum likelihood method. The present analysis estimates EAS cores using the LDD of electrons that fall on the scattered array detectors from the simulated EASs initiated by proton and iron primaries. Considering a densely packed detector array, including configurations akin to GRAPES-3, the research employs a straightforward weight average method (WAM) for the EAS core estimation. The findings reveal that around 95.5% of simulated showers exhibit EAS cores within a deviation range of approximately 1 m to 3 m from the actual cores of the CORSIKA Monte Carlo showers initiated by proton and iron primaries.