Archived - Brian McDermott Plasma Pictures and Fusion Star

[Brian McDermott]

I achieved my first plasma today at about 11:45am. I was unable to go above
5500 volts due to pressure constraints and current limiting. After valving off
the chamber, the pressure rises fairly quickly. Either there are morbid
amounts of outgassing, or there is a real leak, most likely in one or more of
the swagelock connections.

This picture was taken at 1500 volts @ 10 mA. I would reach extinction at
about 7 microns and be unable to go above 5500 volts. Even then, the
current being drawn rarely exceeded 5 mA. The pressure in these particular
photos is around 15 microns.

Later on I managed to get to 11,000 volts, no x-rays or star mode yet. There
is definately a real leak somewhere, as I cannot get below 7 microns with the
pump alone. BUT...

I closed the valve and turned the pump off, and let the pressure leak back up
to 15 microns on its own. Then, through glow cleaning alone, I got the
pressure back down to 6 microns! Later on, with the micromaze
added and about an hour of glow cleaning, I could get to 1 micron. At that
point, the power supply is no good and a discharge cannot be ingited.

I couldn't keep it there though once I valved the chamber off, so that's why I
think I have a real leak. The pressure is back to 700 microns after an hour,
but it never quite gets back to atmospheric even after 3 days. Comments?

I echo the sentiments of others; you really need to see the plasma in person
to appreciate the beauty of it. It is dynamic and ever changing, and can range
from a deep purple to a bright blue in color. I spent some time using magnets
to play with the electron beam (which jumped around a lot), and I noticed a
tiny, but very bright, orange sparkle where the beam met the wall of the
chamber.

For reference, the inner grid is a bit wider than 1.5 inches.

The lower picture is a smaller version of the picture posted in a reply to this
message. This is what the system looks like when putting
out about 10^4 neutrons/sec or so. This is a high quality fusion star typical of
the system.

Please see http://www.brian-mcdermott.com for more pictures.

[Brian McDermott]

I tried making a smaller grid, but any 5 or 6 wire grid under 1.5" seems to be a no go because my spotwelder is too big. I can only make 3 wire grids under that size. The electrode arms can't fit through the gaps in the geodesic unless the gaps are wider than 5/8."

[Brian McDermott]

The pump inlet is just at the edge of the screen. The hose is 30" long and it takes less than 3 minutes to get to base pressure (I have a shorter, 20" length as well). Unfortunately, there really is no other space for the vacuum pump except for that spot on the floor, and I'm literally tripping over stuff as it is with this current setup. That's what happenes when you are exiled to a corner of the garage. Something makes me think think there is backstreaming as the whole inside of the fusor chamber smells like hydrocarbons.

Another thing I noticed is that, below 15 microns, I can't consistantly draw full current unless I place magnets on the surface of the chamber. At lower pressures and higher voltages, I get a lot of flickering rather than smooth control. The flickering increases or decreases in speed depending on where I set the potentiometer. At lower voltages and higher pressures, The plasma is nice and stable and I can control the poissor size and structure quite easily.

[Brian McDermott]

This is a recent image of star mode fusion on October 29, 2004. This is at 20kV and 8mA. The pressure was about 15 microns during the whole run. Isotropic output is about 10^4 neutrons per second. More photos at http://www.brian-mcdermott.com.

This photo was not retouched.

[Brian McDermott]

Updated with a better star mode picture.

[Richard Hull]

Good man Brian!!

This is how it is supposed to be done!! As your post was archived, you have a right to update it at any time with the best images. Thanks for the continued sharing.

Richard Hull

[Brian McDermott]

New star mode picture: 10/29/04.