Conceptual design of a 50m telescope with large-aperture and wide-field for optical and infrared surveys

Abstract

We present a conceptual design for a novel next-generation 50m aperture telescope, the Spherical Wide-field Extremely Large Telescope (SWELT), optimized for both wide-field spectroscopic surveys and high-precision photometric observations in the optical and infrared bands. To achieve the very large aperture with a large field of view (FOV), a spherical primary mirror and with a set of array correctors positioned before the primary focus. The primary mirror is segmented which is selected to balance fabrication complexity, cost, and active correction performance. And based on preliminary estimates, the favoring size of the segments is approximately 1.5–2 meters in corner to corner. An innovative solution to the telescope mounting structure beyond the conventional alt-azimuth designs is considered for a goal of a highly stiff structure with minimal mass, ensuring dynamic stability and low operational costs for the massive 50-m aperture. The design highlights the balance between large aperture, wide-field capability, and cost-effective construction, paving pathway towards next-generation ground-based optical/infrared telescopes.