Fusor V - yet another whack at it.

[Richard Hull]

I would think these tiny cubes are a bit different. They are so jammed up and tight, glass smoothness is a must to keep arc-over from presenting a danger. This is why I left the 2.75 conflat cross within 1 month internal arcing to the sharp joints so close to the grid. Fine at 20kv but no good at 40kv. 6-inch crosses can go on up there in voltage with sharp edges at the arms without arcing. The cubes in-effect have no arms but still need the glass like smoothness all throughout the chamber. This is why I note they are really just a small near-sphere. True spheres need no polish whatsoever, but are still a form of multi-beam on target system. I might imagine dividing the net current and thus neutron production at the beam points among them. With the true cubes, all the current and beaming is divided by 2 instead of 4 as in a 3 looped grid sphere.

Richard Hull

[Jon Rosenstiel]

For reference...

The arms of a 2.75 conflat cross have a bore of 1.375-inches.
My cube's bore is 1.875-inches, 1/2-inch larger than that of the 2.75 CF.
The arms of a 4.5 CF cross have a bore of 2.37-inches, 1/2-inch larger than that of my cube.

Jon Rosenstiel

[Richard Hull]

The higher pressures at voltage also benefits the fusor fusion numbers, regardless of type or design.

Richard Hull