Proceedings Article | 4 February 2004
Robert Stern, Lawrence Shing, Paul Catura, Mons Morrison, Dexter Duncan, James Lemen, Tim Eaton, Peter Pool, Roy Steward, Dave Walton, Alan Smith
Proc. SPIE. 5171, Telescopes and Instrumentation for Solar Astrophysics
KEYWORDS: Iron, Imaging systems, Photons, X-rays, Quantum efficiency, Charge-coupled devices, Spatial resolution, Back illuminated sensors, Space operations, X-ray imaging
A new Solar X-ray Imager (SXI) using back-illuminated, anti-blooming
CCD technology will become part of the instrument complement on
NOAA's GOES (Geosynchronous Orbiting Environmental Satellite) N and
O spacecraft, with probable launch dates beginning in the 2004-2005
time frame. SXI N and O were developed under a NASA contract by the
Solar and Astrophysics Laboratory at the Lockheed Martin Advanced
Technology Center, and are currently being integrated into their
respective spacecrafts by Boeing Space Systems. SXI N and O will
each provide full disk images of the Sun from 0.2 to 1.2 keV (10-60
Å) through the combination of a grazing incidence telescope,
bandpass filters, and an X-ray imaging CCD. The custom designed,
back-illuminated CCDs were fabricated and initially tested by
Marconi Technologies (formerly EEV Ltd, now e2v technologies),
screened in visible light by the Mullard Space Science Laboratory,
and fully characterized in both visible light and X-rays at LMSAL.
By minimizing the field-free region within the CCD, the spatial
resolution at low X-ray energies was significantly improved. The SXI
CCDs also exhibit only very modest response changes as a result of
solar X-ray exposure, based upon extended life tests. The flight
CCDs meet or surpass all specifications for quantum efficiency (QE),
spatial uniformity, defects, charge transfer efficiency, QE
stability in vacuum, read noise, linearity, full well and dark
current. A QE model based on earlier work with ion-implanted,
laser-annealed CCDs provides a consistent picture of the CCD
response from soft X-rays through far UV wavelengths.
