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Geoffrey Thomas First Plasma

Posted: Mon Aug 21, 2017 5:23 pm
by Geoffrey Thomas
The chamber I used is an old bioreactor that I converted to hold vacuum.

Unfortunately, the bioreactor had all kinds of ports which I plugged the best I could with random feedthroughs, so the thing leaks like a sieve, but its a start.

The chamber is pyrex with stainless steel blanks and retainers at both ends, and has 3 bnc coax feedthroughs, a high voltage insulator that I printed out of ABS, a nine pin D-sub connector, and a small gas needle valve with a vernier gauge which I plan to use for ion gun stuff.

My power supply is based around a Plastic Capacitors inc. HV100-103M that I salvaged from an electron diffraction apparatus along with the voltmeter and voltage divider. It has 2 25kv-rated relays which allow me to switch the device from positive to negative hot on a whim by means of a switch. The voltmeter does not always display correctly when the device is under load for some reason. It was built according to the faq on this topic. anybody got any idea what might be causing it not to go fsd?

I also have 4 high frequency modern 40kv 1kw supplies I salvaged from a giant CO2 laser, but I don't want to use them on this small glass chamber for safety reasons.

The pump is a Welch duoseal 1400 that I built from three separate 1400's that were in various states of damage and were being thrown out by RPI, where I go to school (found in a dumpster). While I don't have a TC gauge yet, it seems to be working ok. I have flushed it 5 times and the flushing fluid still comes out pitch black. considering taking the pump housing apart.

For the trial pictured, I bottomed out the vacuum spring gauge, was running the power supply at 8KV (tested without load since the voltmeter is wonky) at 10 mA.

I had the power supply hooked up to my panel variac so I could measure total system current draw.

Time to watch the eclipse,


Re: Geoffrey Thomas First Plasma

Posted: Mon Aug 21, 2017 6:09 pm
by Richard Hull
I have placed you in the Plamsa club.

Richard Hull