8 A 15 ◦ Wide Field of View Imaging Air Cherenkov

Contemporary imaging air Cherenkov telescopes (IACT) for ground-based very high energy (VHE) gamma ray astronomy have prime focus optical design. Typically these telescopes have a (2−4)◦ wide field of view (FoV). They use f/0.7−f/1.2 optics and provide (3−10) ′ resolution in the FoV. Generally, a well designed telescope that includes more than one optical element will offer some advantages not available in prime focus designs, such as a wider FoV, a more compact size, a higher and more homogeneous resolution and a lower degree of isochronous distortion of light rays focused onto the focal plane. Also, they allow monitoring the gamma ray activity in a sizeable portion of the sky in a single observation. This would allow one to perform a sensitive all-sky survey in a relative short time. We present an f/0.8 15◦ wide FoV telescope design, which provides a high and near uniform resolution and low isochronous distortion across the entire FoV.