Astronomical Spectrometers
A number of investigations have been performed to observe the gamma-ray spectra of the Sun and other astronomical sources, both galactic and extra-galactic. The Hard X-ray/Low-Energy Gamma-ray experiment (A-4) on HEAO 1, the Burst and Transient Spectrometry Experiment (BATSE) and the OSSI (Oriented Scintillation Spectrometer Experiment) on CGRO, the C1 germanium (Ge) gamma-ray instrument on HEAO 3, and the Ge gamma-ray spectrometer (SPI) on the ESA INTEGRAL mission are examples of cosmic spectrometers, while the GRS on the SMM and the imaging Ge spectrometer on the RHESSI satellite have been devoted to solar observations.
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