Troubleshooting guide

about face-level in height. Do not stand close enough to the vent such that liquid nitrogen can
splash you in the face!
• Close the valve on the storage dewar, and remove the line from the inlet port of the LN
2
manifold, then
close the silver valve and loosely screw the brass cap back in place. CAUTION: Do not
simultaneously close both manifold valves and the storage dewar valve. This traps liquid nitrogen
within the fill line, with potentially nasty consequences.
3. Remove the MOS dewar window cover.
The MOS dewar window is continuously flushed with dry nitrogen gas from an annular copper ring mounted
on the top of the dewar connected by a hose to one of the dry nitrogen regulators on the telescope backplate.
During the daytime the MOS dewar window is covered by a plastic cover (recycled Frisbee) which also fits
over the copper ring, ensuring that the window environment remains clean and dry. This cover must be
removed prior to observing and and replaced at the end of the night or if one closes due to weather.
Begin standing on the north side of FLAMINGOS, facing south:
• On top of the MOS dewar you should see two large tubular sliding aluminum panels, with their
junction directly in line with the guide camera. Slide the panels open and away from each other.
• Using a flashlight, look inside. The Frisbee has a cutout for the guider pickoff mirror, but is otherwise
not secured in place.
• Carefully reach in and lift the Frisbee off of the window. You may have to rotate it slightly to clear
the guide pickoff mirror. Do not scratch the window or guide pickoff mirror during this procedure.
• Slide the panels back together. Make certain there is a ~3 inch gap remaining, so that light from the
pickoff mirror still makes it to the guide camera, and that the nitrogen hose is not crimped.
4. Create a data directory for the night on flamingos1a.
From any flamingos1a window:
2mguest@flmn-2m-1a{5} cd /data/2mguest/
• Create a directory on flamingos1a with the UT date in the format YYYYMMDD (or whatever
designation you prefer), e.g.,:
2mguest@flmn-2m-1a{6} mkdir 2003sep15ut
• Verify that flamingos1a has sufficient available disk space. Typing df -h on flamingos1a shows the
following output:
Filesystem Size Used Avail Use% Mounted on
/dev/dsk/c1t0d0s0 9.3G 1.3G 7.9G 15% /
/dev/dsk/c1t0d0s1 9.3G 2.7G 6.5G 29% /usr
/dev/dsk/c1t0d0p0:boot 11M 1.7M 9.0M 16% /boot
swap 951M 12K 951M 1% /var/run
swap 961M 9.2M 951M 1% /tmp
/dev/dsk/c1t1d0s0 68G 29G 38G 44% /data
/dev/dsk/c1t0d0s2 16G 2.5G 13G 17% /home
FLAMINGOS@2.1-m, Ver. 2.39, 2011 May 13 Page 12 of 46