(privileges may be required)
(privileges may be required)
To give new operators a feel for what it is like to run a night with the Array, a representative night will be demonstrated using the Classic instrument and operated remotely by an observer in Atlanta.
It's April 15th and the sun sets at 7:24 pm. It's a Wednesday, so Judit will do the alignments this afternoon. Arrival on the mountain by 5:30 will give plenty of time to set up and take care of any problems that arise. The schedule shows C2 (Classic program 2) for tonight, that's Tabby Boyajian's program. Tabby is a good observer, so it should be a smooth night.
The weather is ok, but a few clouds passing through should be gone by tonight. The IR satellite view shows one more band that needs to blow through. Seeing won't be great, but it's April, what do you expect. At least Classic will do better than than the visual programs in poorer seeing. Tabby has already emailed the observing plan for the next four nights, so no surprises there. A check of CHARA email shows that there were no mechanical problems and minimal other issues reported after last night's observing. I'll head up at 4:30 to arrive at 5:30.
As I arrive at the CHARA office, I see Laszlo and Judit's car. I'll find her in the lab after getting set up in the control room. I set up my laptop and bring up Skype to see if anything has come in from Tabby. No messages yet, but it's still early, almost two hours until sunset. A check of the email shows nothing new since this morning.
Since the last clouds have passed, I could open the domes, but I need to find Judit first to confirm that she has finished with the alignments in the lab. As I walk into the computer area, I see that the vacuum valves are closed and a check of VACMON shows that the vacuum levels are still pretty low from last night, so she has not turned the pump on. I power up the VME as I walk by and head out to the pump house to turn it on. As I open the door to the pump house, I see the temps on the monitor. The oil temp is 32ºC and the air is 39ºC. The pump starts quietly at that temp when I flip the switch and as the blower comes on, I open the valve. I close the latch on the door, but leave it unlocked until the morning.
Back in the computer room, I open the valves on S1 and S2 just a little. They have the highest leak rate and can pump down slowly as I fill the cameras in the lab. I'll do E1 and E2 when I come back out. Judit is inside finishing up the alignments to the IR table and will do the M10 alignments out in the computer room. I can fill the cameras while she does that. Looking at the log book, I see that Steve filled the cameras this morning. Since he comes in so early, the cameras will take a little extra LN2 than if they were done later in the morning. After putting on the goggles and cryo gloves, I bring two funnels, the thermos, and the 35 liter LN2 dewar over to the 1``