Background
The ESI CCD dewar is cooled by liquid nitrogen (LN) cryogen in
order to maintain the detectors at their optimal operating
temperateres of -120 C. This webpage describes adopted
practices in achieving accepable dewar vacuum, timescale for
cooling the dewar after a warm fill and for warming the dewar when
cryogen is exhausted.
Acceptable Vacuum
TBD
Cooldown Curve
The following plot shows the behavior of the dewar temperature
following a warm fill. The dewar can typically achieve the
standard operating temperature within about 2.5 hours after the
LN warm fill.
Click to enlarge
Warmup Curve
TBD