Archived - USM Fusion Group: First Light

[Ed Meserve]

Last night we achieved first light on our demo fusor. We don't have a capacitor inline on our power supply, so it was devilishly tricky to get pictures with it blinking. We are nailing down a couple more details before the Engineering Expo next weekend.

Ed

[Chris Bradley]

Could you explain the kit arrangement here? It looks like you are using some sort of flask and a plastic screen around it, rather than a bell-jar? I can't make it out.

I'd guess your pressure is quite high also, ~100 microns. What is you current vacuum pumping kit?

[Ed Meserve]

Chris,
You're right on, we were only able to get down to .1 torr (100 micron). The pump we are using is a Welch 1400. the base plate is a machined 1" thick aluminum, and the lines are flared copper gasline tubing. The valve is also gasline stock.
All threads were sealed with 5 min. apoxy, though not the flares on the lines. Couldn't quite decide what to do with those.

The vacuum chamber is piece of pyrex process pipe modified with Ace Thred fittings.

The screen is just .25 " plexi.

[SteveHansen]

When you get your Pirani gauge hooked up you can do some basic leak detection using a gas that isn't air. Probe the various connections with the test gas and look for a spike up or down on the Pirani reading. I often use "dust remover" spray if He or Ar isn't readily available. Having the Pirani connected to an A/D and a running pressure vs time graph really helps.

Steve

[Richard Hull]

It is good enough for the Plasma club. I have added the USM group to that listing.

Good luck.

Richard Hull

[acaldarone]

Damn fine first light.