First observational results with the prototype experiment of stereoscopic water Cherenkov detector in Tibet

The SWCDA (Stereoscopic Water Cherenkov Detector Array) is a next-generation ground-based gamma-ray observatory that introduces significant technological innovations to existing Extensive Air Shower (EAS) array detection techniques. This advanced system achieves an order-ofmagnitude improvement in sensitivity over conventional ground arrays for gamma-ray observations in the 100 GeV to 100 TeV energy range, while lowering the detection threshold from 500 GeV to 100 GeV. Its unique capabilities - including a wide energy coverage range ( 100 GeV - 100 TeV), a wide field of view, and high duty cycle - enable complementary observations with future gamma-ray facilities (CTA, SWGO, ALPACA and LHAASO), and contribute to multi-messenger astronomy through coordinated observations with neutrino and gravitational wave detectors. The primary scientific objectives focus on extragalactic sources, particularly transient phenomena such as blazars, active galactic nuclei (AGNs or AGNs flare), gamma-ray bursts (GRBs), and Galactic microquasars to study gamma-ray acceleration mechanisms across the energy spectrum. The detector system consists of two core components: a Liquid Scintillator (LS) array and the SWCDA array. We present detailed performance characteristics and initial observational results from a 100 m2 SWCDA prototype deployed within the Tibet AS𝛾 air-shower array in late 2024, demonstrating its potential for advancing high-energy astrophysics research.