Parabolic Grid Experiments

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Frank Sanns
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Parabolic Grid Experiments

Post by Frank Sanns »

Many posts about anisotropy of neutron output and beam on target devices. I thought I would assemble and experiment that might give an idea of what is going on with some of these.

Attached are some pictures of my setup. The dual SS mesh grid arrangement uses a 3" large grid that is parabolic in shape. The small grid is flat. As you know, I do not like symmetry in my experiments. Imperfect things sometimes shed light on mysteries or things that would normally go unnoticed.

The grids are attached to a thick ceramic stalk as a support for the experiment. I have clipped off the sharp corners so there is less chance for pointed corner edge effects. Not sure it was necessary but I was eating a 10" copper gasket to place the experiment so I did not want to do it twice.

These were run with air and only at around 4KV. I am going to do another series with deuterium and at 30-40KV with lower pressures. I just wanted to post these as they are interesting to see what is going on with beam on target. In this case, a mostly transparent target.
Sanns Parabolic Fusor Grid Side CR.jpg
Sanns Parabolic Fusor Grid CR.jpg

The next series of pictures will use various HV arrangements on each of the grids.

The first is a positive large grid and a grounded small grid. This is the convergence that I had expected. No so with other polarities. I will post a follow up with some of my observations.
Sanns Parabolic Grid Large Positive HV Small Grounded.jpg

Here is a photo with the large grid grounded and the small grid at HV. There is much more structure and beam crossings than the photo shows.
Sanns Parabolic Grid Large Grounded Small Negtive HV.jpg
And one with the large grid with a positive HV and the small grid with a negative HV.
Sanns Parabolic Grid Right Positive Left Negative HV.jpg
Achiever's madness; when enough is still not enough. ---FS
We have to stop looking at the world through our physical eyes. The universe is NOT what we see. It is the quantum world that is real. The rest is just an electron illusion. ---FS
Frank Sanns
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Re: Parabolic Grid Experiments

Post by Frank Sanns »

No neutrons? No deuterium gas? No low pressure? What gives.

Well, I have in the past seen that plasma "modes" change as the pressure decreases. The most important changes for fusion happen close to where the pressure drops from 30 microns down to 10 microns. That is what this picture show. Those final glimpses of plasma before the paths get every long and their origins become clouded or disappear.

1. Sharp edges at low pressures do not concentrate the fields very much at all. At atmospheric pressure this grid would be arcing from the edges. No need to snip sharp corners at fusion pressures.

2. The large positive HV grid and grounded small grid gave the most classical behavior of parabolic dishes. There was convergence of the plasma from the "dish" onto the horn.

3. The small negative HV grid gave a beam response. It did not originate at the far corners of the large grounded grid. It originated mostly in the center and beyond it. This is interesting. It was almost like the large grid was not even there. Letting the large grid float or be grounded did not change this behavior.

4. Powering both grids also gave a surprising result. It seems that when the larger grid is positive and the smaller one negative, a hybrid of the two modes is not really seen. It is almost like the worst of both worlds is what comes out.

Adjusting the power on each of the polarities changed the look of things quite dramatically. Most noted is the lighter blue plasma that forms behind the larger grid. This is most noticeable when the power (voltage) is a little higher on the large grid than the smaller. It swells or shrinks as the power rations between the grids are changed. Why a different color? Why doesn't more voltage push more toward the small grid rather than escape behind it? Is the blue clouds electron rich then and the redder ones ion rich?
Achiever's madness; when enough is still not enough. ---FS
We have to stop looking at the world through our physical eyes. The universe is NOT what we see. It is the quantum world that is real. The rest is just an electron illusion. ---FS
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Richard Hull
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Re: Parabolic Grid Experiments

Post by Richard Hull »

Good work. If any fine mesh is used, electrostatically in appears and is treated as a solid plate. Tesla and others classically educated knew this and his Wardencliffe tower's giant terminal appears as a miriad of spoked ends in the shape of a oblate paraboloid. Some think he never covered it with metal. However, he did not need to cover it with metal as it acted as a smooth electrostatic spheroid due to the closeness of the metal blunted spokes. Both electrostatically and capacitively, it behaved as a solid. there are a number of electrostatic field equations that can calculate the critical separations to achieve this uniform capacitive appearance to the air dielectric or in a vacuum or partial vacuum as the external dielectric constants remain unity. As with any terminal capacitance, there is a voltage at which it breaks down. In a lower pressure regime the arcing occurs at a lower voltage, but in a high vacuum 10e-6 torr vacuum arcing voltages climb through the roof. This is why the giant van degraffs use to be placed under vacuum. Some modern systems are vacuumed to 10e-5 and then back filled with pressurized SF6.

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
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