Pre-launch calibration campaign of the gamma-ray spectrometer aboard the INTEGRAL satellite

Abstract

The SPI, Spectrometer aboard the ESA INTEGRAL satellite, to be launched in 2002, will study the gamma ray sky in the 20 keV to 8 MeV energy band with a spectral resolution of 2 keV for photons of 1 MeV thanks to its 19 germanium detectors. A coded mask imaging technique provides for a 2° angular resolution. An active BGO veto shield is used for background rejection. After the integration and test campaigns at CNES in Toulouse, the flight model of SPI has recently undergone a 1 month pre-launch calibration campaign at the CEA center of Bruyères le Châtel, using an accelerator for homogeneity measurements and high activity radioactive sources for imaging performance measurements. We report on the operational aspects of those measurements, whose analysis is foreseen to be published before launch.