IBIS/PICsIT in-flight performances

Abstract

PICsIT (Pixellated Imaging CaeSium Iodide Telescope) is the high energy detector of the IBIS telescope on–board the INTEGRAL satellite. PICsIT operates in the gamma–ray energy range between 175 keV and 10 MeV, with a typical energy resolution of 10% at 1 MeV, and an angular resolution of 12 arcmin within a ~100 square degree field of view, with the possibility to locate intense point sources in the MeV region at the few arcmin level. PICsIT is based upon a modular array of 4096 independent CsI(Tl) pixels, ~0.70 cm2 in cross–section and 3 cm thick. In this work, the PICsIT on–board data handling and science operative modes are described. This work presents the in–flight performances in terms of background count spectra, sensitivity limit, and imaging capabilities.