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Instrument: HESSI IMAGER
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Associated Platforms
RHESSI

Spectral/Frequency Information
Wavelength Keyword: X-Ray
Number Channels: 1

Related Data Sets
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Description
The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) Imager
consists of the Imaging Telescope Assembly, which consists of the telescope
tube, grid trays, Solar Aspect System (SAS), and Roll Angle System (RAS). It
was constructed, assembled, aligned, and tested at the Paul Scherrer Institut
in Switzerland. The front and rear grid trays are attached to the telescope
tube (shown here). It maintains the separation and alignment of the trays.

Nine grids are mounted on a grid tray at each end of the telescope tube. The
grid pairs modulate the transmission of solar flare x-ray and gamma-ray
emissions through to the detectors as the spacecraft spins around the axis of
the telescope tube. The modulated count rates in the nine detectors are used in
computers on the ground to construct images of solar flares in different energy
bands.

The five coarse grids (square) were constructed by Van Beek Consultancy in The
Netherlands. The four fine grids (round) were constructed by Thermo Electron
Tecomet in Massachusetts. All grids were characterized both optically and with
X-rays at Goddard before being shipped to the Paul Sherrer Institut for
integration into the imaging telescope assembly.

For more information, see:
http://hesperia.gsfc.nasa.gov/hessi/instrumentation.htm

Online Resources
http://hesperia.gsfc.nasa.gov/hessi/instrumentation.htm

Instrument Logistics
Instrument Start Date: 2002-02-05
Instrument Owner: NASA/GSFC