ONE of the coolest boards on the net?!!
The configuration you describe was tried on HEPS back around 1985, then on PXL-1, and finally on WB-5, all mentioned in Bussard's October 2006 report. There are pictures of PXL-1 and WB-5 in there ... the magnets are outside the box. See if that's what you had in mind.
http://www.askmar.com/ConferenceNotes/2 ... 0Paper.pdf
The original idea was to produce a wiffle ball trapping factor so high it worked as you say. In practice, the cusp losses were never low enough at high electron kinetic energy. But for the MaGrids, the cusp losses are not losses, they recirculate. One of the big conclusions of the report is that the HEPS-type configuration will never work. The MaGrids will.
I ran PXL-1. That machine did some neat stuff, which included trapping electrons until it just couldn't hold any more. My supposition was it plugged the cusps with low-energy electrons that could be held by mag mirror effect, then those repelled the higher energy electrons. Not realizing why the machine had apparently gone quescient, I once made the mistake of turning off the magnets before it had bleed off the stored electrons. The electrons going to the walls evidently coupled energy into the magnets and shoved a huge load of current back into the battery bank for half a second, blowing a damper diode and causing a huge bang from the magnet contactor. That was when I finally realized that the machine acted like a capacitor, but one that worked with a flux of moving electrons. In other words, it was (everybody groan together) a FLUX CAPACITOR!
Alas, we could never get it to do this trick with a deep enough potential well. WB-5 attempted to use modified cusps to try to enhance the effect, but it didn't work well enough.
