The future ground-based gamma-ray observatory CTA

During the last couple of years, ground-based gamma-ray astronomy has witnessed a major breakthrough with the physics results obtained by the current generation of imaging atmospheric Cherenkov telescopes. In order to exploit the full physics potential of this field, the next generation instrument – the Cherenkov Telescope Array CTA – aims for an improvement in sensitivity by an order of magnitude with respect to current experiments, an extension of the accessible energy regime from some tens of GeV into the 100 TeV range, and for an improved angular and energy resolution [www.cta-observatory.org]. CTA will be operated as an observatory, open to a wide scientific community, not only to attack astrophysical questions, like the origin of Galactic cosmic rays, but also to find answers to fundamental questions like the constitution of Dark Matter. A world-wide collaboration of more than 100 groups has formed to face the challenge of developing a cost-effective design of CTA. After about four years of intense work on the design of CTA, the project has entered its FP7-funded Preparatory Phase, with the goal to be ready to start implementation by the end of 2013.