All internal surfaces providing optical baffling are black painted using vacuum-qualified paint. The cryostat contains a carbon getter with its own thermal circuit-breaker protected getter heating element and temperature sensing elements. The focal plane mount is on a similar yet completely independent thermal stage. Strict attention was paid to dewar materials and construction to maintain low outgassing and high vacuum. The optical layout is shown here .
All optical surfaces are anti-reflection coated.
A cold stop is placed at the pupil image. Here is a dark map and here is a flat field as received from Rockwell. The total detector readout and delivery time is expected to be of the order of 3 seconds with the second generation SDSU controller. Commands can be issued either from a GUI form or at the command line level, the latter feature allowing relatively complex sequences of observations, such as dithering and mosaics, to be prepared in advance using C-shell scripts. The CFHT-IR filters have been integrated into the CFHT Interference Filter Database and their detailed characteristics can be retrieved here .