I have a quick question, does the shape of the vacuum chamber effect the operation of a fusor? For example the majority of the fusor devices that I have seen here have been sphericle in shape, however one or two have also been simple pieces of capped pipe.
My question therefore is what is the most optimal shape for the vacuum chamber? Is there an optimal shape?
Sincerely
Melvin Newman
Shape of vacuum chamber
Re: Shape of vacuum chamber
Spherical is really elegant, looks cool, and minimizes the surface area for the vacuum pump to fight. It is probably best.
You can make a perfectly fine machine in any shape chamber by putting a spherical outer grid in the chamber. Aligning the wires of the inner and outer grid is one trick for achieving a good star mode.
I've done a couple of fusors by putting the spherical inner grid into any old chamber, with no outer grid. Generally these were cubes, one was a big bell jar. All lit off nice glows and several were used to make some fusion.
You can make a perfectly fine machine in any shape chamber by putting a spherical outer grid in the chamber. Aligning the wires of the inner and outer grid is one trick for achieving a good star mode.
I've done a couple of fusors by putting the spherical inner grid into any old chamber, with no outer grid. Generally these were cubes, one was a big bell jar. All lit off nice glows and several were used to make some fusion.
Re: Shape of vacuum chamber
Here is a secondary question, does the inner grid have to be spherical? Can it be say a cube? I ask this more as a conceptual question.
- Melvin Newman
- Melvin Newman
Re: Shape of vacuum chamber
People here seem to take great pride in making theirs as spherical as possible.
However, the highest count rate I recall producing was on a grid make by a 17-year-old nephew of Dr. Bussard, one of the sloppiest darned things you can imagine. The power supply in this case was an enormous thing we had built for the MaGrid machines, capable of over an amp at 10-13 kV. I forget how many counts that thing made during a runaway ... it was even less spherical afterwards, but it worked.
Matching the inner and outer grid shapes encourages star mode, but that doesn't mean they must be exactly spherical, and changes to the shape to encourage the star to form is an area where amateurs may make considerable strides.
However, the highest count rate I recall producing was on a grid make by a 17-year-old nephew of Dr. Bussard, one of the sloppiest darned things you can imagine. The power supply in this case was an enormous thing we had built for the MaGrid machines, capable of over an amp at 10-13 kV. I forget how many counts that thing made during a runaway ... it was even less spherical afterwards, but it worked.
Matching the inner and outer grid shapes encourages star mode, but that doesn't mean they must be exactly spherical, and changes to the shape to encourage the star to form is an area where amateurs may make considerable strides.
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denergyguy
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Re: Shape of vacuum chamber
I was thinking that if you have a positively charged inner shell it would tend to repel any charged items towards the center due to the location of it's focus. Could using shapes that increase the number of foci have an impact on the number of fusions?
Re: Shape of vacuum chamber
I have I think the same question, can the central grid be eliminated if the outer grid is positively charged?
Re: Shape of vacuum chamber
If the outer grid is positive with respect to the walls, the ions born at the outer grid will go to the walls.
If both are positive, then there is no gradient to accelerate the ions.
But ... if the outer walls and grid are grounded, and there's a fairly large inner grid that is positive, then you have the electron-accelerating equivalent of a Fusor, the Elmore-Tuck-Watson machine. The dense region of ions produced in the center is a virtual fusor, and will attract ions without the grids.
George Miley and others have worked with pulse timing, to attract bursts of ions to the accelerating grids, but reverse polarity as they pass so they don't hit the grid. That idea probably has some merit.
If both are positive, then there is no gradient to accelerate the ions.
But ... if the outer walls and grid are grounded, and there's a fairly large inner grid that is positive, then you have the electron-accelerating equivalent of a Fusor, the Elmore-Tuck-Watson machine. The dense region of ions produced in the center is a virtual fusor, and will attract ions without the grids.
George Miley and others have worked with pulse timing, to attract bursts of ions to the accelerating grids, but reverse polarity as they pass so they don't hit the grid. That idea probably has some merit.