The Medium-Sized Telescope (MST) will be built by an international collaboration of institutes and universities from Austria, Germany, France, Brazil, Poland, Spain, Switzerland and the Italy. This will be CTA’s “workhorse,” with sensitivity in the core energy range of CTA, from about 150 GeV to 5 TeV. The planned baseline for CTA includes 40 MSTs – 25 in the southern hemisphere and 15 in the northern hemisphere. The MST mirror will be about 12 metres in diameter and will have two different camera designs that use photomultiplier tubes (PMTs). The MST cameras will have a large field of view of about 8 degrees, enabling the MSTs to take rapid surveys of the gamma-ray sky.
The MST is a modified Davies-Cotton telescope with a reflector diameter of 12 m on a polar mount, and a focal length of 16 m. The MST will have up to 90 hexagonal-shaped mirrors that are aligned with an active mirror control assembly to create a uniform reflector.