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National Aeronautics and Space Administration

Goddard Space Flight Center

Astrophysics Science Division | Sciences and Exploration

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Energy Range: 20 to 8000 keV
No. of Germanium Detectors: 7
Energy Resolution: 1.8 keV @ 500 keV (composite for all 7 detectors)
Ge Detector Type: high-purity n-type coaxial
Ge Detector Size: typically 6.5 cm diam. x 6.5 cm length
Total Ge Detector Area: 242 cm2
Total Ge Detector Volume: 1560 cm3
Shielding: NaI active anticoincidence (15 cm min. thickness)
Field-of-View: 17 degree FWHM @ 500 keV
3 Sigma Narrow Line Sensitivity: 1.7 x 10-4 ph cm-2 s-1 (E = 500 keV, T = 12 hr)
Pointing System: azimuth over elevation; momentum wheel for azimuth control; magnetic reference; star camera and sun sensor for verification
Power: 350 W
Experiment Weight: 1634 kg (3600 lbs)
Telemetry Rate: 55.2 kbps
* Parameters are those achieved in GRIS Flight II.

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