Research Update June 8

Kind of mundane work today, or maybe it’s just that I’m only writing to keep up the habit and I just really want to go to bed. Let’s get through the highlights.

I closed the angle valve and the pressure in the ion pump went up a decade and half before coming down. It finally settled at ~1 x 10^-8 T! What the heck. Why the huge pressure bump? Why is one pump just as good as two? Either way I wrapped up and stored the turbo pump. It’s nice to have that off the table and out of the way.

I spent way too long this afternoon trying to get the breadboard back on under the MOT chamber. The trick that finally worked? Wedging the faztek nuts in approximately the right place with little balls of aluminum foil to hold them while I installed the board. Even then I still only got 3 out of 4 screws in. I’ll have to check once more to make sure the board doesn’t need that last one.

Scare with the 461 nm laser system today. It was on… and then it wasn’t. and there was no IR power registering on the ammeter. I quickly turned the system off. Then I noticed that the temperatures on both the TA and the master were off the set point. The TA was at ~11 C and the master at ~22 C. A tweak and both came back. However, this put the master about 2 wavenumbers lower than the transition. I finally got it back close by setting the temperature around 25 C. I’ll have to remember to write that down tomorrow so that I don’t forget. When I was running the system later there was a sudden decrease in power on the TA and the current was suddenly running about .6 A lower than it should have been. Very scary and very frustrating. I don’t know if it’s electrical noise or soft power cycling that seems to be rewriting new values to the DAC, but if it turns off the TA while it’s coupled I’m screwed.

Tried to see absorption in the cell one last time and finally had to cool it and reinstall the cartridge heater. I was just getting an optically dense strontium vapor when I had to shut down for the day. Here’s crossing my fingers for tomorrow.