Studying Ultra-High-Energy Cosmic Rays Using an Artificial Expansion of the Telescope Array Surface Detectors Spacing

Ultrahigh energy (UHE) cosmic rays are the most energetic particles known in nature, eclipsing the energy of those produced at man-made accelerators by a factor of more than a million. The Telescope Array (TA) Project is an experiment designed to measure the arrival direction and energy of these particles by utilizing the largest array of scintillator detectors in the northern hemisphere. The TA began data collection in 2008 with an original surface detector (SD) array composed of 507 detectors with 1.2 km spacing, organized in a square grid. Due to the observation of potential sources, the collaboration plans to expand the array by an additional 500 detectors with a larger 2.08 km of spacing. The expansion, known as TAx4, would quadruple the original aperture of the array. The first 257 of the TAx4 detectors were deployed into the field in 2019, however, the remaining detectors have been delayed due to the pandemic. Recently, we artificially split our original TA SD array into two checkerboarded SD arrays with 1.7 km of spacing in an effort to more quickly complete our TAx4 expansion while also preserving our main TA SD array. We have tested the efficiency of our new SD configuration using Monte Carlo simulations, and here we report on the expected performance of our new SD array configurations.