No leaks during a bakeout of up to 450 C, the base pressure with just the ion pumps is in the low 10-11 torr range, and the residual gas analyzer shows nothing but a little hydrogen left. I think we can call this a success.
The outside of the chamber isn’t quite as aesthetically pleasing as it was, but the inside is very, very clean, and ready for installation of windows, and the lithium vapor sources. Next: move it to the main table and get ready to attach the main chamber.
We’ve made some major progress this week with the assembly, pump-down, and bake out of the new 2DMOT chamber for 6Li and 7Li.
There are no indications of leaks so far with the blanked-off chamber baking at 250 C. If things still look good tomorrow, we’ll we’ll heat most of the chamber (especially the appendages that will house the lithium vapor sources) to >400 C to drive hydrogen out of the chamber walls.
The temperature in the central part of our lab is now stable to within ±0.05 C.
It’s been a complicated and needlesly drawn out technical battle to get to this point. For comparison, here’s a plot of what the HVAC system was doing to the lab temperature shortly after it was commissioned, over a year ago. (Emerson/Liebert, you are permanently blacklisted as far as we’re concerned)
Needless to say it wasn’t easy to make progress getting the lasers stabilized in an environment like that. Now that we’ve got a proper laboratory to work in, we should be able to make a lot more progress in the next 12 months!
K. C. Wright, R. B. Blakestad, C. J. Lobb, W. D. Phillips, and G. K. Campbell
