Germany – Astronomical and optical instruments – DESY Zeuthen: CTA-MST Pathfinder Optical Support Structure Components Manufacturing

DESY is one of the world's leading accelerator centres and a publicly funded national research centre of the Helmholth Association in Germany. Researchers use the large-scale facilities at DESY to explore the microcosm in all its variety. Zeuthen is (besides Hamburg) the second location of DESY, located in the south-eastern outskirts of Berlin. Since 2011, the DESY Zeuthen campus has been profiled as a globally visible center for astroparticle physics. DESY Zeuthen is involved in several international research projects in astroparticle physics. The Cherenkov Telescope Array Observatory (CTAO) is a ground-based observatory for gamma-ray astronomy. With 64 telescopes spread across the northern and southern hemispheres, CTAO will be the most sensitive instrument for studying high-energy phenomena in the Universe. Work on building the observatory has just begun. DESY is responsible for the development and construction of the Medium-Sized Telescopes (MST) for CTAO. In the first phase, two Pathfinder telescopes will be built at the southern observatory site near the ESO Paranal observatory in Chile. The structure of the telescope is mainly made of steel. The reflector diameter of the telescope is 12 m and consists of 86 hexagonal mirror segments with a side-to-side width of 1.2 m. The Optical Support Structure (OSS) is mounted on a positioner. The OSS can be moved to any point in the sky within 90 seconds. The movement is performed by two motorized rotation axes integrated in the azimuth drive unit and for the elevation in the head of the positioner. The telescope's camera consists of a matrix of almost 2000 photomultiplier tubes located at a distance of 16 m from the eflector.