E.H. Wishnowa,b, W.C. Danchia, P. Tuthilla,
R. Wurtzb,
J.G. Jernigana, J.F. Arensa
aUniversity of California Space Sciences Laboratory
Berkeley, CA, 94720-7450
bV Division
Lawrence Livermore National Laboratory
Livermore CA 94550
The Long Wavelength Infrared Camera (LWIRC) is a facility
instrument for the Keck Observatory designed to operate
at the f/25 forward Cassegrain focus of the Keck I telescope.
The camera operates over the wavelength band 7-13 
m using
ZnSe transmissive optics. A set of filters, a circular
variable filter (CVF), and a mid-infrared polarizer are available,
as are three plate scales: 0.05'', 0.10'', 0.21'' per pixel.
The camera focal plane array and optics are cooled using liquid helium.
The system has been refurbished with a 128
128 pixel Si:As
detector array. The electronics readout system
used to clock the array is compatible with both the hardware
and software of the other Keck infrared instruments NIRC and LWS.
A new pre-amplifier/A-D converter has been designed and constructed
which decreases greatly the system susceptibility to noise.
Mid-Infrared Camera, Astronomical Instrumentation, 10 Micron Camera, Si:As FPA