PROCEEDINGS ARTICLE | January 12, 2004
Proc. SPIE. 5167, Focal Plane Arrays for Space Telescopes
KEYWORDS: Infrared detectors, Infrared sensors, Optical filters, Mercury cadmium telluride, Cameras, Sensors, Quantum efficiency, Space telescopes, Multiplexers, Hubble Space Telescope
Wide Field Camera 3 is a fourth generation instrument for the
Hubble Space Telescope (HST), to be installed during the next HST Servicing Mission 4. For its infrared channel Rockwell Scientific Company has developed a new type of HgCdTe 1Kx1K detector, called WFC3-1R, with cutoff wavelength at 1.7μm and 150K operating temperature. The WFC3-IR detectors are based on HgCdTe MBE grown on a CdZnTe substrate and use a new type of multiplexer, the Hawaii-1R
MUX. Two flight detectors, a prime and a spare, have been recently selected on the basis of the measures performed at NASA Goddard Research Center - Detector Characterization Laboratory. These parts show quantum efficiency higher than 80% at λ=1.6μm and greater than 40% at λ>1.1μm, readout noise of ~25 e- rms with double correlated sampling, and mean dark current of ~0.04 e/s/pix at 150K. We show that the IR channel of WFC3, equipped with one of these flight detectors, beats the instrument requirements in all configurations and promises to have a discovery efficiency
significantly higher than NICMOS. In particular, a two-band
wide-area, deep survey made with WFC3 exceeds the discovery
efficiency of NICMOS before and after the installation of NCS
by a factor of 15 and 10, respectively.
