RGA Baseline

25 02 2011

All photos.

I’ve decided to adjust my research by taking smaller steps more frequently.

Yesterday I installed the RGA to get a clean baseline for the vacuum system.

It didn’t detect much! Which is good news:

I also spent HOURS organizing the lab. Getting wires off the floor, shelving, etc:

And got a stethoscope for future vacuum diagnostics:

RGA Progress

27 09 2010

All photos.

I tried the RGA today and finally made some progress. Check this out:

Looks like the RGA works, but it still needs calibration.

Seems we have hydrocarbons and water in the chamber. Where did O2 come from (or is that air)

Wonder what mass 26 and mass 30 and 29 are?

Here is partial pressure over time:

I doubt I’m even using it right. There is a lot to learn.


14 10 2009

Took another crack at the RGA. Got a lot further this time.

Previously we used the sensor in the flange it shipped in, but this flange did not hold a vacuum.  I removed the sensor:


And reinstalled it like this:

More after the jump.

Read the rest of this entry »

Progress Update

12 08 2009

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:IMG_3920

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:


RGA Update

12 07 2009

I received the swageloks and coaxial cable for the RGA unit. I fired up the vacuum pump, but it seems the RGA unit is not holding a vacuum. I’m guessing it’s a leak with one of the swageloks. Looking into it.

RGA setup

9 06 2009

Gearing up to try out the Residual Gas Analyzer . Waiting on some Swagelok end caps and coaxial cable. The computer system is setup with the RGA software installed. All the physical parts are connected.  I’m reading through the manual.


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