The MST is a modified Davies-Cotton Imaging Atmospheric Cherenkov Telescope with a reflector of 12 m in diameter and a focal length of 16 m. Two different camera designs have been developed for the telescope. Its large field of view of 7 degree will enable the MST to take extensive surveys of the gamma-ray sky. The telescope structure is designed to host both camera types, allowing to exchange them on the telescope, without major modifications.
The collaboration for the MSTs include institutes from Germany, France, Brazil, Poland, Switzerland, Italy, Czech Republic, Austria and Spain. DESY leads the "structure" work package, which is responsible for all components of the MST except the Cherenkov camera. The telescope structure is made primary of steel components. The mirrors are realised as spherical facets of hexagonal shape with a 1.2 m side-by-side length and 32.14 m radius. The reflector is composed of 86 identical segments which are fixed to the telescope dish structure using two actuators and one fix point. To ensure high availability and low long-term maintenance efforts most of the electrical components are installed in cabinets inside the tower. Despite the cooling chiller and the UPS (for the northern observatory site) no external housings and containers are used. Automatic lubrication for the azimuth and elevation drives as well as a novel telescope structure and drive components monitoring system allow remote maintenance and failure diagnosis of the most critical elements.
A full-size mechanical prototype of the telescope structure was constructed by DESY in Berlin in 2012 and has been operated until February 2020. Various tests of hardware and software were performed. The performance is being evaluated and optimizations, among others, facilitating the assembly procedure and mass production possibilities are being implemented.
The design of the positioner, i.e. the tower with the azimuth and elevation drive system, has raised interest of other projects. It is used in the final version by the prototype Schwarzschild-Couder Telescope in Arizona, while the initial prototype is being adapted to be used for BabyIAXO, a telescope in search for dark-matter particles emitted by the Sun.
