Talk-Polywell.org

A picture of my concept of the Funnel Analogy for the Wiffleball. My text descriptions are often wordy and perhaps ambiguous, but since a picture is worth a thousand words...

There is the Bussard idea of the "Wiffle Ball" toy that the effect is named for. Also, I have mentioned analogies of a pool table or a Funnel.

This picture shows the Funnel analogy. Some funnels were glued to card board squares. Assuming a cube with a funnel on each face, it is shown with a larger diameter funnel and a smaller. This represents the smaller cusp size with increased B field strength.

Also shown is a funnel where almost all of the collecting cone has been cut off. This shows the effect of the Wiffleball flattening of this portion of the cusp while pushing out the surface of the Wiffleball. My nomenclature describes the funnel collecting area as the cusp throat, while the drain hole is the cusp proper. These arbitrary labels serve to show that the cusp collecting area decreases considerably, while the cusp proper or drain hole is not actually shrunk or pinched. It remains unchanged in this analogy.

Also, note that the surface area of the cube side also increases as the Wiffleball inflates (the funnel cone is cut off) and this increases the total surface area of each side of the cube.
So two processes are occurring. The total surface area is increasing and the cusp / funnel loss areas are decreasing. The Wiffleball trapping factor would reflect the product of both processes. In this pictorial example the cusp/ funnel loss area decreases by a factor of ~ 20 while the total surface area increases by a factor of ~ 1.5 for a total gain of ~ 30X. Compare this with claims that the Wiffleball trapping improves confinement by a factor of ~ 50-100 X . In the patent application claimed improvement is ~ 60 passes for cusp confinement and ~ several thousand passes for Wiffleball confinement. This analogy/ model shows similar improvements without needing to invoke pinch processes (which are inherently unstable) or unreasonable geometry changes. The Wiffleball process seems straight forward in concept. Implementation may be a different matter.

One side of a cube was used to keep the visualization simple. It could be extended to a truncated cube or higher order polyhedron if desired.



Dan Tibbets

If I read correctly, when the plasma pressure is low – the leaks in containment are large and the plasma volume is small.




And as the plasma pressure increases the plasma occupies a larger volume, with smaller leaks.

Mattman,
Take your grey sphere in the low pressure case and instead of having holes, put outward pointing funnels. Then as the sphere grows in pressure it gets larger, but the funnels stay where they are, so the hole gets smaller as it moves out the funnel.

Yes.

Think of it as a puffer fish sort of thing.

To go back a couple of years to what my son coined in regard to Polywell: "Spikeyball"

I was thinking it may be useful to show it using some ballons for each element.

Toroidal ballons for the coils. Then a normal spherical ballon in the center for the plasma sphere.
Inflate the "magnet" ballons to a set pressure.

Then, slowly start inflating the "Plasma" ballon in the center.

Yup, almost got it. Now the only things missing are the line-like cusps that exit between the magnets. They will be more like a knife edge than a funnel.

This anything close? A shape bounded by pressed toroids.

Deleted, duplicate post.

The form of the spikey ball (IMO) is a little more severe. Longer spikes, deeper concave curves. Smaller effective average diameter.
Then take that, and do what Kite is saying, run one at a larger effective diameter within the constraints of the toroids, then another at a smaller effecttive diameter. Then pick a distance from the center of the plane of one of the toroids, and measure down along the perpendicular axies towards the center of the spikey ball. At the picked distance then measure the diameter of the "throat" for the spike you have measured down the axis on. This will give you an idea of the comparison of the "wiffleball effect". Ie. Big throat, small throat. If you play with it, it will also give you an idea of the dynamics regarding the interplay between plasma pressure and B-Field. Beta = 1 is the max Plasma pressure before the B-Field can no longer contain. The operating zone, as argued and mostly agreed on here over several years, is a Beta just under 1.
The wiffle ball zone is where the non-linear curve of the spike throat cone is the smallest at the highest Beta. Note that due to the non-linear nature of this cone curve, that there is a point where increasing plasma pressure does not bring a significant change in throat diameter (farther out on the spike).

This is a MATLAB map of the magnetic field pressure in WB6 in the XY plane. I drew in the Whiffle Ball effect in dark blue.

I like your second start.
This time, start with a smaller cube.
Pull the face point out beyond the torus, maybe half the distance between the cube face and the mid-plane of the torus.
Pull the cube corners about the same radial distance out.
Pull the cube edges out a similar distance.

Then, start with a bigger cube and do those three things again, except since the cube face is closer to the mid-plane, the points, corners, and edges will be pulled out a shorter distance.

Getting there!