Today I tweaked the electron gun.
My goal is to bring the electron gun closer to ground. This should reduce the pressure needed to strike a plasma.
I used Stuart’s DIY spot welder to make a hoop from welding wire:
I installed this hoop on the electron gun:
This arrangement brings ground potential closer to the electron gun.
And it worked somewhat.
With this hoop, I can strike a stable plasma at 18 millatorr. Better than yesterday’s 25 millatorr. Still needs work to get back to 8.5 millatorr.
When I went to fire the coils I discovered my SCR is shot:
Turns out the SCR’s peak current is 2,000 amps. At 2,300 amps we are well beyond that!
I have to order a new SCR tonight. Suggestions welcome.
Elsewhere… I drilled a hole in the langmuir probe holder to allow trapped gas to escape:
Also tested out the supercapacitors in my friend Arnie’s forklift:
They were able to lift Arnie twice!