AGILE, a satellite for high energy γ-ray astrophysics: prospects for the Mini-Calorimeter

AGILE is an ASI (Italian Space Agency) small space mission for high energy astrophysics in the gamma ray energy range 30MeV–50GeV, and in the X-ray band 10keV–40keV. AGILE is composed of three scientific detectors: a TungstenSilicon Tracker, a CsI Mini-Calorimeter and a Silicon based X-ray detector (Super-Agile), moreover an anticoincidence system carries out background rejection. The satellite’s payload will have good imaging performances (with angular resolution of a few arc-minutes in the gamma ray band), good timing resolution and a large field of view (about 1/5 of the sky). AGILE detection principle is based on the pair production process that arises from the interaction between high energy photons and the Tungsten layers of the Silicon Tracker. The Silicon Tracker is designed to determine the direction of the incoming radiation, while the Mini-Calorimeter evaluates the energy of the interacting photons. The Mini-Calorimeter can also work as a stand-alone gamma ray detector in the energy range 250keV–250MeV, with no imaging capabilities, for the detection of transients and gamma ray burst events (in cooperation with Super-Agile) and for the evaluation of gamma ray background fluctuations. In this paper a description of the Mini-Calorimeter is done.