Characteristics and performance of GAW, Gamma Air Watch – a path-finder of a new generation of Imaging Atmospheric ˇ Cerenkov Telescope with large field of view

摘要

GAW, acronym for Gamma Air Watch, is a path-finder experiment designed to test the feasibility of a different technological approach for Imaging Atmospheric ⅶ Cerenkov Telescopes. GAW differentiates from the existing and presently planned telescopes for two main features: the adoption of a refractive optics system as light collector and the use of single photoelectron counting as detector working mode. The optics of GAW, composed by a custom-made 2.13 diameter single-sided Fresnel lens, will allow to achieve large field of view capability (8 】 8). The focal surface consists of a matrix of multianode photomultipliers. The large number of active channels (of the order of 105) makes it basically a large UV sensitive digital camera with high resolution imaging capability. GAWis being mounted at the Calar Alto observatory, Spain, 2150 m a.s.l., and its calibration phase is planned to start in 2012. GAW is a collaboration effort of several Research Institutes in Italy, Portugal and Spain. Keywords: ⅶ Cerenkov Telescopes; TeV astronomyAbstract: GAW, acronym for Gamma Air Watch, is a path-finder experiment designed to test the feasibility of a different technological approach for Imaging Atmospheric ⅶ Cerenkov Telescopes. GAW differentiates from the existing and presently planned telescopes for two main features: the adoption of a refractive optics system as light collector and the use of single photoelectron counting as detector working mode. The optics of GAW, composed by a custom-made 2.13 diameter single-sided Fresnel lens, will allow to achieve large field of view capability (8 】 8). The focal surface consists of a matrix of multianode photomultipliers. The large number of active channels (of the order of 105) makes it basically a large UV sensitive digital camera with high resolution imaging capability. GAWis being mounted at the Calar Alto observatory, Spain, 2150 m a.s.l., and its calibration phase is planned to start in 2012. GAW is a collaboration effort of several Research Institutes in Italy, Portugal and Spain.