Large Size Telescopes

The LST project team consists of more than 100 scientists from eight countries: Brazil, France, Germany, India, Italy, Japan, Spain and Sweden. Because gamma rays with low energies produce a small amount of Cherenkov light, telescopes with large mirrors are required to capture the images. Four Large Size Telescopes (LSTs) of 23 m diameter and 28 m focal length will be arranged at the centre of both the northern and southern hemisphere arrays to cover the unique low energy sensitivity of CTA between 20 and 200 GeV. The LSTs will also have a very good sensitivity up to energies of several TeV, which is, however, covered by MSTs more efficiently.

The LST is an alt-azimuth telescope. It has a parabolic reflective surface, which is supported by a tubular structure made of reinforced carbon fiber and steel tubes. A reflective surface of 400 square metres collects and focuses the Cherenkov radiation into the camera, where photo-sensors convert the light in electrical signals that can be processed by dedicated electronics. The total weight of the telescope is around 100 tons.

Photo Credit: Mero-TSK, International; MPI, Munich

Preparatory Phase work packages specifically related to the large-sized telescopes are:

Large-sized Telescope System Engineering and Integration

Design of the Large Telescope Structure & Optics, and component Prototyping

Design & Prototyping of the Large Telescope Camera