CTA - The Medium Size Telescopes

The Medium Size Telescopes (MST) of the Cherenkov Telescope Array (CTA) are are the core components of the observatory, providing sensitivity in the core energy range of CTA, from about 100 GeV (gigaelectronvolt) to beyond 10 TeV (teraelectronvolt). The current baseline of the observatory includes 25 MSTs in the southern hemisphere and 15 in the northern hemisphere.

Each MST reflector is 12 meter in diameter and consists of hexagonal mirror facets with a size of 1.2 meter each. Two different designs have been developed for the camera of the telescope. Its large field of view of 7-8 degree will enable the MST to take extensive surveys of the gamma-ray sky.

The collaboration for the MSTs include institutes from Germany, France, Brazil, Poland, Switzerland, Italy, Austria and Spain. DESY leads the "structure" work package, which is responsible for all components of the MST except the Cherenkov camera. A full-size mechanical prototype of the telescope structure has been constructed by DESY in Berlin in 2012. Various tests of hardware and software have been performed and are currently ongoing. The performance is being evaluated and optimisations, among others, facilitating the assembly procedure and mass production possibilities are being implemented.