TGRS
in scheme: instruments
definition: The Transient Gamma-Ray Spectrometer (TGRS) on WIND will detect transient gamma-ray burst events and will make the first high-resolution spectroscopic survey of cosmic gamma-ray bursts, and will also make measurements of gamma-ray lines in solar flares. Cosmic gamma-ray bursts are among the most violent and energetic processes known to exist in nature, characteristically emitting most of their luminosity at gamma-ray wavelengths. The high-resolution spectroscopy of solar flares will contribute to the study of solar flare activities and help in understanding the coupling between the active corona and photosphere. The TGRS instrument consists of four assemblies: detector cooler assembly, pre-amp, and analog processing unit, all mounted on a tower on the +Z end of the spacecraft, and a digital processing unit mounted in the body of the spacecraft. The detector is a 215 cubic cm high purity n-type germanium crystal of dimensions: 6.7 cm (diameter) X 6.1 cm (length), radiatively colled to 85 degrees K. The germanium serves as a reaction medium for incoming gamma rays, which, depending on their energy, are either stopped by or passed through the detector crystal. Particle energy and angle of incidence are calculated based on a number of primary and secondary interaction processes, including photoelectric, Compton, pair and bremsstrahlung radiation as well as the ionization energy losses of secondary electrons. A two-stage cooler surrounds the detector, providing a field of view of 170 degrees. Gamma-ray bursts and solar flares are expected to be detected at a frequency of several per week, with typical durations between 1 second and several minutes. Between bursts the instrument is maintained in a waiting mode, measuring background counting rates and energy spectra. When a burst or flare occurs, the instrument switches to a burst mode, where each event in the detector is pulse-height analyzed and time tagged in a burst memory. Then the instrument switches to a dump mode f…
type: Concept

X-Ray/Gamma Ray Detectors
type: Concept