Todd T. From Swagelok stopped by the shop and we quickly built a parts list for the deuterium system and the RGA. Turns out we are using a VCR style Swageloks, and they require a single use steel gasket much like the copper gasket in a conflat.
Also made a first pass at building the persistent switch. Here you see 50cm of insulated nicrome wire wrapped around 5cm of YBCO:
Cover in Kapton tape:
Connect a multi meter across the YBCO, and wire up the nicrome wire to a variable power supply:
And into the cold:
Unfortunately I was not able to get any reliable readings from the ohm meter. Before I turned the heater on, the meter registered between -0.5 ohms to 0.4 ohms. Any change in resistance from turning on the heater was lost in the meters margin of error. However the heater does turn on and work. You can hear the LN2 boiling off when you set the heater current to about 1.5 amps. So not exactly sure how to meter and test the persistent switch… for all we know this one works. And really this makes perfect sense: the resistance of the multimeter probes should be greater than the strip of superconductor even in it’s resistive state.
Coming out of the LN2: