Mike Wilson - Plasma

[Mike Wilson]

I just finished testing out a crude fusor setup and had some unexpected results after running. The first image is shortly after the fusor was first lit. Unfortunately, I can't seem to get the pressure low enough to have a proper ball, the plasma seemed to stay around the wires. The setup is running ~7.5 kV @ ~28 in Hg.

After some time, there seemed to be a flashlight effect on the far chamber. The grid is a little more open on that side than I would have liked. Does anyone have an idea of what may be causing the effect? As I lowered the voltage from 7.5 kV, the flashlight effect stayed there until I reached ~750V. At this point, most of the grid had gone dark and only the very bottom was still lit. Once the voltage was lowered a little more, the flashlight effect quit and the grid was lit more at the HV input.

[Richard Hull]

Please note that a vacuum measured and reported in inches tells us absolutely nothing at all about what you have. You can report in bars, pascals, torr or microns, but never in inches, provided you want to inform us about what kind of real vacuum you have there.

Most here report in microns as most of the gauges set up for technical vacuums that you might acquire relatively cheap are in microns. Deeper, scientific vacuums are usually reported in Torr using scientifc notation. If you are a stickler for SI units, which it appears you are not, you can report in those units and send the bulk of us scurrying about for a conversion table to Torr.

Your vacuum is very poor and that is why you are not producing a good central ball and bugle jets which are signs that you are at least somewhat close to the mark, but even then, have a way to go.

My guess is that you are at about 500 microns. A good technical vacuum is about 20 microns. Got a long way to go.

I put you in the Plasma club.

Richard Hull