Thursday, November 17, 2005, 16:00
WHGA Auditorium
A. Zehnder, PSI
Abstract:
In October 1997 the High Energy Solar Spectroscopic Imager (HESSI) was
ranked first in the NASA SMEX (Small-Class Explorer) selection and was
launched Feb. 5, 2002. HESSI provides unique imaging spectroscopy with
up to 1% energy resolution and up to 2 arcsec. angular resolution of
solar flares in the X- and gamma rays in the range from 3 keV to 20 MeV.
Moreover, it observes a number of non-solar objects, in particular the
Crab Nebula and gamma-ray bursts. The PSI delivered the imaging
telescope, the solar- and star based aspect systems needed for the image
reconstruction as well as the corresponding on-board computer,
electronics and software. After launch HESSI was renamed in honor of
Reuven Ramaty to RHESSI. It was designed for a 3-year lifetime, but due
to its successful operation and science output, the operation time was
extended. A summary of the instrumentation is given followed by a
sampling of the major science results.