R. Mirzoyan et al., THE FIRST TELESCOPE OF THE HEGRA AIR CHERENKOV IMAGING TELESCOPE ARRAY, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 351(2-3), 1994, pp. 513-526
In search of VHE gamma ray emission from cosmic point sources a system
of imaging Cherenkov telescopes is constructed at present on the Cana
rian island of La Palma; the first telescope has been operational sinc
e 1992. The Cherenkov light from air shower particles is collected by
a 5 m(2) reflector. The camera at the focus contains 37 photomultiplie
rs which sample the images of the Cherenkov flashes. The subsequent im
age analysis allows the discrimination of gamma ray induced events fro
m the much more abundant charged cosmic ray induced showers. The teles
cope has an effective energy threshold for gamma showers of about 1.5
TeV. During the first year of operation a signal from the Crab nebula
was detected.