Simple 'Polywell' like demo
Posted: Wed Jan 28, 2009 7:19 am
Needing something to do with surplus magnets harvested from microwave ovens I mounted 6 donut shaped magnets in a cube, similar to a Polywell to see what it would do to the plasma appearance in my Pressure Coooker demo fusor.
It shows the limited 'confinement' of this low energy plasma with edge cusps losses apparently larger (brighter) then the point/ center cusps* (with the N. Pole intercepting the face of the perminate magnets there are actually two 'zones' to consider - center cusp to magnet face, and edge cusp to magnet face because of the unfortionate interception of the plasma by the North pole of the magnets on the inner faces of these permanate magnets. To avoid this, I would have to use electromagnets or glue a bunch of disk magnets end to end to form a ring (?).
I have no idea of the strength of these magnets. Making some optamistic guesses, I wander if an extension of this simple setup could be used to study (at least visually) some of the plasma/magnetic interrelationships without needing electron guns, ion guns, gas puffers, etc. Just use the cathode grid for the electron source and residual air/ helium/ etc for the ion source.
Link that includes photo
http://www.fusor.net/board/view.php?bn= ... 1233125450
* Difficult to appreciate in the photo, it is more obvous visually.
Dan Tibbets
It shows the limited 'confinement' of this low energy plasma with edge cusps losses apparently larger (brighter) then the point/ center cusps* (with the N. Pole intercepting the face of the perminate magnets there are actually two 'zones' to consider - center cusp to magnet face, and edge cusp to magnet face because of the unfortionate interception of the plasma by the North pole of the magnets on the inner faces of these permanate magnets. To avoid this, I would have to use electromagnets or glue a bunch of disk magnets end to end to form a ring (?).
I have no idea of the strength of these magnets. Making some optamistic guesses, I wander if an extension of this simple setup could be used to study (at least visually) some of the plasma/magnetic interrelationships without needing electron guns, ion guns, gas puffers, etc. Just use the cathode grid for the electron source and residual air/ helium/ etc for the ion source.
Link that includes photo
http://www.fusor.net/board/view.php?bn= ... 1233125450
* Difficult to appreciate in the photo, it is more obvous visually.
Dan Tibbets