The vacuum pump for IGRINS is only good for low-pressure use.
If IGRINS was recently opened in the cleanroom then a larger roughing-pump will be required to get started (taking 36-72 hours).
To refresh the vacuum on IGRINS when it is being stored at McDonald:
Let the cryostat warm to ambient temperature.
Plug the vacuum pump into UPS power.
Attach the vacuum pump and turn it on, letting the vacuum line be fully evacuated with the turbo pump running.
Slowly open the vacuum valve. There will not be a noticeable change in the noise since IGRINS is already at low pressure.
Leave IGRINS on the pump for 2-3 days.
Before disconnecting the pump start the coldhead so any remaining gas condensates and freezes on the charcoal box.
Remove the vacuum pump when the pressure is <5e-6 torr, after a few hours of cooling.
To remove the pump:
close the valve
shut down the pump and let the turbo spin down
disconnect the valium hose