EXES pumping and LN2 filling before IRTF run

Here are the notes from Lars and IRTF about EXES pump down and cooling at the IRTF.....

12-17-10 @ 11:30: pump pressure 7.2e-5 Torr. Valve off dewar. Shut off pump.

@15:00: pump manifold 7e-2 T.

12-22-10 @ 11:00: pump manifold 2.5 T.

12-29-10 @ 9:45: cracked dewar valve (with pump on). pressure rise to 2e-3 T.

@13:00: 9e-4 T.

@15:30: 5e-4 T.

12-30-10 @04:20: 8e-5 T

@15:00: valve closed. 5e-5 T

1-2-11: ~19:00: valve opened. P 4e-4 T.

1-3-11 @10:30: pump at 5e-5 T. Start filling outer can with LN2. Pressure dropped. Valve closed.

@10:45: outer can full. switch to inner can.

@11:30: inner can full. switch to outer can (still full).

@12:00: topped off before lunch (still had some liquid) - NOTE: not certain which can.....

@14:00: inner can empty, outer still fuming. topped off both cans. 15 min on inner.

@14:25: storage dewar empty

@14:50: new dewar. restarting N2 can fill

@15:30: last top off, both cans.

@21:15: outer still fuming. inner empty. fill inner. push in screwdrivers. top/middle echelle may not have clicked in, but rest moved in nicely.

@21:30: inner full

@21:40: start data logger to CD11.txt (1 second intervals changed soon to 1 minute)

@21:45: start filling outer can

Temps: A=113.3; C2 = 74.129; D4=73.907; D2=107.45

@22:00 outer full.

@22:15 Temps: 111.21; 73.85; 73.74; 104.17.

@23:15 top off inner. took 5 minutes. outer had low enough boiloff to leave. try to push in screwdrivers, but all pretty solid.

@23:30 head down.

updated 1-4-11@12:20: both cans still full with low boil-off. plan to fill before leaving or when they run out (will not fill inner since we will be pumping soon). temperatures available in cd11.txt

updated 1-4-11@15:00: both cans still have liquid. filled outer can (5 minutes). put LN2 into inner can for 2-3 minutes (since we'll be pumping tomorrow, didn't want it full). Changed temp log rate to 5 minutes.

1-5-11@10:30 - rotated EXES to 3 clicks short of vertical so that LN2 runs out of cans (necks down). Start pumping on inner can. Using backing pump on turbo. Have gauge on pump and installed our pressure gauge on neck tube port. Have balloon on one-way valve to check for leaking. Have plastic in-line valve connecting two lengths of blue hose. in-line valve is cracked right now. getting ~7 torr at pump and ~450 and dropping on our gauge. temperature coming down. going to let sit for a bit before opening in-line more. filled outer can.