The DEIMOS hatch is controlled from The
Dashboard GUI. It is air pressure driven and extended
stationary periods can lead to pressure bleed. If a move fails,
first try re-sending the move.
DEIMOS has several lamps available for wavelength calibration.
These include: Argon, Krypton, Xenon, Cadmium, Neon, Zinc, and
Mercury. There is also a Quartz lamp for internal flat
fielding. Please note that the Cd, Zn, and Hg lamps require 3
minutes minimum warm-up for wavelength stability. Most
observers take their wavelength calibration frames and flat
fields via the Slitmask Calibration
Tool. By default, the exposure times in this tool are set
for the 1200G grating at 7800Å central wavelength. For
other setups, please check the Exposure Recipes page.
The DEIMOS shutter is of the air pressure-driven, double-pass
type. The shutter is susceptible to pressure bleeds after
periods of inactivity that cause the shutter move to fail.
Before your first night time exposures, we recommend you
exercise the shutter a few times to ensure correct operation.