SPI calibration

The 20 keV to 8 MeV energy range (SPI) spectrometer is a 19-germanium detector array, with a coded mask and a BGO anti- coincidence shield. It will perform spectral analysis of compact objects such as black holes and neutron stars, and map gamma-ray-emitting regions resulting from supernova explosions. The aim of the calibration is to obtain the instrument energy response and its imaging capability over its full energy domain. From 20 keV to 2 MeV one can use current radionuclides, but from 2 up to 8 MeV it is necessary to produce the γ-ray lines through accelerator induced reactions. The CEA/DAM Bruyères-le-Châtel 4 MeV accelerator has been chosen for this purpose. At the same time, high-intensity sources, situated 150 m away from the telescope, will be used.