The AGILE gamma ray satellite

AGILE (Light Imager for Gamma-ray Astrophysics) will be launched on an equatorial orbit in 2007 by the PSLV Indian launcher. It is a small scientific satellite for the detection of γ -ray cosmic sources in the energy range 50 MeV–30 GeV with a field of view of 1 5 of the sky, and will become the only detector in that energy range till the launch of GLAST. Three different detectors and an anticoincidence system are the components of the scientific instrument. The main detector is a silicon–tungsten tracker. The second detector is a X-ray detector in the range 15–45 keV; its main aim is to highlight the X-ray emission associated to the gamma emissions. The third detector is a small calorimeter made of 30 CsI scintillating bars read out by photodiodes; its energy range is 150–300 keV. The large number of channels (about 37 000, with analog read out), requires very reliable components. Each part of the instrument has undergone several tests during the assembly phase; then the whole instrument has been calibrated on a dedicated photon tagged beam-line developed at the DAPHNE BTF (Beam Test Facility, INFN Frascati) and has been integrated with the satellite.