The Large Array of Imaging Atmospheric Cherenkov Telescopes (LACT): Performance and Status

The Large High Altitude Air Shower Observatory (LHAASO) has recently detected over 40 ultra-high-energy (UHE) gamma-ray sources. However, many of these sources are extended, and some are located within a small angular region ( 1°) that LHAASO cannot resolve clearly. To address these limitations, the Large Array of Imaging Atmospheric Cherenkov Telescopes (LACT) has been proposed and is currently under construction at the LHAASO site. LACT consists of 32 telescopes, each with a field of view of 8𝑜. It has an angular resolution better than 0.05𝑜 and a large detection area of approximately 2 𝑘𝑚2 for energies above 10 TeV. Additionally, by integrating parameters from both the showers detected by LHAASO and the Cherenkov images captured by LACT, the array achieves robust gamma/hadron separation capabilities. This enables precise measurements of the energy spectra and morphologies of UHE gamma-ray sources. These capabilities are crucial for resolving the acceleration mechanisms and the origins of cosmic rays. In this presentation, we introduce the design and performance of LACT, discuss the prospects for studying UHE gamma-ray sources, and provide an update on the current status of the experiment.