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Omnidirectional Gamma-ray Spectrometer

The design of the French Gamma Telescope (FREGATE) is based on that of the successful gamma-ray burst experiment LILAS on board the Russian Phobos mission. Its prime objectives are the detection and spectroscopy of gamma-ray bursts and the monitoring of variable X-ray sources.


Two of the gamma detectors are seen right of center.

Built by Centre d'Etudes de Spatiales Rayonnements (CESR, France)
Instrument type NaI(TI); cleaved
Energy Range 6 to 400 keV
Timing Resolution 10 microseconds
Spectral Resolution ~25% @ 20 keV
~9% @ 662 keV
Effective Area 120 cm2
Sensitivity (10 sigma) 3x10-8 erg cm-2s-1, over 8 keV-1 MeV
Field of View 3 steradians