Fusor Power Supply - Initial Plasma test

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Dennis P Brown
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Joined: Sun May 20, 2012 10:46 am
Real name: Dennis Brown

Fusor Power Supply - Initial Plasma test

Post by Dennis P Brown »

Installed the new electrode system on my fusor (see photo.) Then hooked up the power supply (PS) This all worked very well. The current and voltage are controlled by two principle parameters - fusor pressure (which has two controls: DP gate valve and the deuterium leak valve), and the variac setting. Both worked very well and I was able to obtained a stable plasma at 15 kV and 35 ma to 25 kV at 25 ma. The power supply easily handled 35 ma in the teens with no significant heating.

The fusor's digital voltmeter and the milli-amp meters both worked extremely well.

The fusor chamber 'lite' up uniformly and the current readings were highly stable. Only when changing parameters did voltages/currents fluctuated. However, as long as I remained above 6/7 milli-toor, the system tended to operate smoothly.

Since this was a non-deuterium test, I didn't try the top end of the PS - 32 kV at 25 ma. But that should not be an issue considering now well this system worked.

I realized I forgot to ground the 'leak' valve and this forced me to hold a ground wire to this as I adjusted the fusor pressure; while this valve never got voltage, I wasn't going to risk that since these voltages/currents are lethal. I will add that ground system tonight.

Overall, extremely happy with both the operation and especially the performance of the high voltage PS. That x-former easily handled 35 ma at 22-25 kV (short durations; worried about electrode heating.) So, power is excellent. I look forward to seeing how close to 32 kV I get. I know the system can exceed 25 ma at full voltage but isn't rated for above that power for continuous operation. I see no problem with surge runs (a few minutes) up to 35 milli-amps near/at the rated 32 kV my system can get (this upper voltage value, of course, should never be exceeded for x-former safety issues.) Will see if running 30/35 ma at the highest voltage is worth doing but only later after I test normal max power operation against my neutron detector - have time and a real run may need to wait until I get back from Germany.
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Fusor Input Electrode (encased in a covering)
Fusor Input Electrode (encased in a covering)
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Richard Hull
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Re: Fusor Power Supply - Initial Plasma test

Post by Richard Hull »

It is nice to have things go reather smoothly on occasion. Hope you get to fusion soon.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Jeannette
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Joined: Wed Jun 10, 2015 7:30 am
Real name: Jeannette Brown

Re: Fusor Power Supply - Initial Plasma test

Post by Jeannette »

Hello, this is Dennis
Just posting using my daughter's phone to give a progress report of what I did before I left the US; also, first time I have ever used a phone to acess the internet. Currently in Germany at Greifswald - strange that she is off to work at the Max Plank institute of plasma physics while I just chill here at a coffee shop (l know a few words of German but the peoplè here are nice and help me). Just wanted to say, l made a new electrode and with it centered in my chamber the results are much better. The down side, it leaks a little. Still, I managed to get up to 22 to 23 kv at 35 ma. Yet i couldn't keep the plasma stable due to falling pressure! For reasons I haven't figured out, my pressure will just suddenly begin falling. It is frustrating but considering the little time or experience I have, not all that surprising, I guess. When I get back I will order yet another glass blank and build a new electrode - one that is good to 10^-5 torr.
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