Sid Kanwar's Fusor Progress

[Sid Kanwar]

Hi everyone. After researching this project over the summer, I began work on my fusor in late August. I'm happy to share that I have finally achieved plasma this week!

My setup uses a 2.5” Conflat tee & cross for the main chamber. After flushing out the Kozyvacu TA500 Dual-Stage HVAC Vacuum Pump recommended by Joe Ballantyne, I was able to pump the chamber down to 4 microns!

My power supply is a NST transformer graciously provided by Rich Feldman. I reached out to Rich last month to ask for his guidance on this project, as he lives nearby and has a wealth of expertise in this area. I don’t have very much experience with high voltage, and I wanted to make sure that I didn’t electrocute myself. Rich has answered all my questions and provided so many great insights; his inputs have been invaluable in getting to this point.

The NST is connected to a 30kV feedthrough that is attached to a foot-long section of 14 gauge Niobium wire which I have coiled up into a (somewhat lumpy) Meiro spiral.

I've been testing this setup for a few days now. I pumped down from where plasma barely sparked (~12 torr), until it grew to a respectable star (~3.5 torr), and then until it was finally snuffed out (~0.5 torr).

I have attached all images required to gain plasma club membership below.

In this image, you can see the Conflat vacuum chamber with all its exterior modules attached on my apartment floor.

My Kozyvacu TA500

My CPS VG200 Vacuum Gauge reading my lowest pressure, four microns.

Again, thanks to Rich Feldman for lending me his NST transformer! Here, you can see my high voltage voltmeter measures the NST’s output of just above 5 kV.

For now, I’m just using a standard multimeter for my current measurement.

Here's my viewport slightly illuminated by the glow of the inner grid

Here's my feedthrough with the brass coupling and the Meiro spiral

And as promised, here are pictures of my plasma at various pressure levels!

For my next steps, I will definitely be clearing up my messy wiring. I am looking for a cart or table that I can bolt everything down to, and I will upgrade the wiring from alligator clips to something more secure before moving up to fusion-capable levels of electricity. I am also waiting on a 15 mA analog ammeter so I can move away from using my cheap plastic multimeter.

Thanks!

Sid Kanwar

[Rich Feldman]

Good post, SId.
Couple of comments via forum, since more eyes are on the issues now.

1. When putting 15 mA analog meter in series with HV circuit, even on grounded side, it should have some kind of overvoltage-protective shunt in case a thin internal wire fails into an open circuit state. Just like in your kV meter, except with hundreds of times more current. More conventional is a hefty current sense resistor of 10 ohms or less, across which the voltage is measured.

2. As discussed, the conflats need to be reconfigured to put more distance between leak valve knob and HV terminal !

3. As discussed, configuration can have all switches and knobs and meters/gauges facing operator, but not the viewport because of x-ray hazard.