SPI calibration

The 20 keV to 8 MeV energy range (SPI) spectrometer is a 19-germanium detec tor array, with a coded mask and a EGO anti- coincidence shield. It will pe rform spectral analysis of compact objects such as black holes and neutron stars, and map gamma-ray-emitting regions resulting from supernova explosio ns. 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 Me V one can use current radionuclides, but from 2 up to 8 MeV it is necessary to produce the gamma-ray lines through accelerator induced reactions. The CEA/DAM Bruyeres-le-Chatel 4 MeV accelerator has been chosen for this purpo se. At the same time, high-intensity sources, situated 150 m away from the telescope, will be used, (C) 2000 Elsevier Science B.V. All rights reserved .