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Goals: Many future X-ray astronomy missions will need large collecting
area telescopes that are at least an order of magnitude improvement
over the current generation of missions. These large optical systems
must be low mass in order to be lifted into orbit. At the same time as
the mass per unit collecting area must be reduced, the angular
resolution of future X-ray telescopes must be improved. A goal of one
tenth arcsecond resolution over an arcminute field of view, with 10's
of square meters of collecting area has been set for Gen-X, a NASA
Vision Mission for the 2030's.
To achieve these two performance goals is a challenge. There will be
steps along the way. The optics being developed for Constellation-X
will be lightweight compared with the Chandra optics, but will have 5
to 15 arcsecond angular resolution. A small area tenth arcsecond
resolution optic could be the basis of an Explorer class mission that
could study the few very brightest extended X-ray sources. X-ray
optics with good performance over a several arcminute field of view
could carry out large area surveys for clusters of galaxies.
Basic approach: The CXT X-ray optics program is working towards these
goals. The first step is to to improve mirror fabrication
metrology. "You can?t build what you can?t measure". Second is to
determine fundamental limits to mirror fabrication approaches such as
glass slumping, selective deposition, and polishing. Then it is
necessary to determine efficacy of alternative approaches such as
active, or adjustable, optics.
People
Paul Reid, Suzanne Romaine, Mark Freeman, Jon Chappell, Martin Elvis, Stephen Murray
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