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arXiv · 2603.19622

A Concept of Next-Generation Atmospheric Cherenkov Telescope Array (NG-ACTA)

Jiancheng Wang·Jirong Mao
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Abstract

The Next-Generation Atmospheric Cherenkov Telescope Array (NG-ACTA) is proposed as a prospective infrastructure for very high energy (VHE) gamma-ray astronomy, consisting of a mixed-aperture array of 88 telescopes with a maximum array diameter of 10 km. The array adopts a three-tier configuration of 30 m large-aperture Large Size Telescopes (LSTs), 12 m medium-aperture Medium Size Telescopes (MSTs), and 6 m small-aperture Small Size Telescopes (SSTs), enabling continuous gamma-ray detection across the full energy band from 20 GeV to 100 TeV. With core advantages of an ultra-low detection threshold ($\leq20$ GeV), ultra-high angular resolution ($\leq0.04^\circ$), ultra-large effective area ($\geq1\times10^5$ m$^2$), extreme cosmic ray background rejection (proton rejection efficiency $\geq99.99\%$), and rapid transient response ($\leq100$ ns trigger latency), NG-ACTA targets the most cutting-edge and transformative fundamental scientific topics in modern astrophysics and particle physics, including VHE gamma-ray astronomy, cosmic ray origin, multi-messenger astronomy, and dark matter as well as new physics tests. The array's scientific goals cover five core fields: particle astrophysics, VHE gamma-ray astronomy, cosmic ray physics, multi-messenger astronomy, and new physics exploration, with six hierarchical and mutually supportive scientific objectives from Galactic to extragalactic sources, steady to transient objects, and conventional objects to dark matter. A comprehensive comparison with international under-construction facilities (e.g., CTAO-North, CTAO-South) and Chinese facilities (e.g., LACT) demonstrates that NG-ACTA leads the world in low-energy threshold, baseline length, background suppression, and multi-messenger rapid response capabilities.

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Jiancheng Wang, Jirong Mao. 2026-03-20. A Concept of Next-Generation Atmospheric Cherenkov Telescope Array (NG-ACTA). https://arxiv.org/abs/2603.19622

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