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JWST is expected to help find the Universe's first galaxies, essentially linking the Big Bang to our own Milky Way. Peering through dusty clouds, on-board instruments primarily will sense in the infrared region of the electromagnetic spectrum with some visible-range capability.

As the principal imager, the Near Infrared Camera (NIRCam) will address many of JWST's core science goals: detecting early phases of galaxy and star formation and distant supernovæ; galaxy morphology and color at very high red-shift in rest-frame optical wavelengths; mapping dark matter via gravitational lensing; and, studying stellar populations in nearby galaxies.

NIRCam consists of two broad- and intermediate-band imaging units, each with a 2.16×2.16 arcmin field-of-view. The modules have short and long wavelength channels to capture images simultaneously with light split by a dichroic plate at ∼2.35 μm. Short wavelengths are sampled at 0.0317 arcsecs/pixel (4096×4096 pixels) and the long channels are read at 0.0648 arcsecs/pixel (2048×2048 pixels). Each imager has a pupil wheel with extra optics and analyzers for wavefront sensing, a capability which ensures complete redundancy since mission success will depend upon their flawless operation.

The anticipated point-source sensitivity is ∼3.5 nanoJansky for 0.6<λ<5.0 μm over a 100,000-second exposure with a signal-to-noise ratio of 10. All 10 detectors are mercury/cadmium/telluride 2048×2048 arrays (Teledyne Scientific & Imaging, LLC, Thousand Oaks, Ca.). Led by a team at the University of Arizona (Tucson), NIRCam currently is under construction and receives additional support from Lockheed-Martin's Advanced Technology Center (Palo Alto, Ca).

Contributing editor and industry analyst, Lee J. Nelson, is at the forefront of emerging as well as evolving technologies for compute-intensive electronic imaging applications. Contact him at 1-703-893-0744, lnelson@rcn.com or http://www.garlic.com/biz