jcoady, Recirculation indeed refers to electrons being recirculated (probably through the same cusp after they escape through a cusp to the space outside the magrid. The magrid in most of the Polywells had a positive charge on the magrid. This positive charge serves to accelerate the electrons from the electron guns ( the guns in this configuration only emitted low energy electrons by thermogenic means- perhaps at ~ 12 V). My understanding is that this electrostatic acceleration of escaped electrons back through a cusp is equivalent to the acceleration of the new electrons from the electron gun. If the escaping electrons have been upscattered too much (>~2,000eV) above the potential well and ~ equal to the potential on the magrid they will be slowed but not reversed. In this case you are both removing nasty upscattered electrons, but most(?) of this upscattered energy is recovered. So the recirculation not only recovers most electrons at very little cost, and impedes progressive electron up scattering at only a modest cost. The magrids are direct energy converts (like those discussed for P-B11 fusion, but these are designed to recover the the energy (most) of the escaping electrons. So long as the electrons have not accumulated to much KE (~ 12 KeV in the WB6 example) the electron will be stoped while transfering the KE to the grid, they will then be acellerated back into the magrid, the energy expendature balance should be very small. The electrons that have more than 12 KeV energy in an outward direction will only retain the fraction above 12 KeV,.
To correct the ion collisions- the ions need a few thousand Coulomb collisions before a fusion collision is likely to occur. To allow annealing to work, only a few coulomb collisions could occur (mostly near the center) or possibly less than one collision on each transit through the Wiffleball space. How many times an ion is likely to transit the system before escape has not been well quantified publicly. It is generally accepted (by us optimists) that the ions transit many more times before loss compared to electrons, in fact Bussard has hinted, that most of the ions may fuse before they escape. This high fuel burn up is needed for several reasons (to limit external vacuum pumping, to minimize ion escape energy losses (the magrid would accelerate the ions as they left which would add to the overall losses)). That Bussard, etel claim that electron losses dominate over ion losses implies that this is the case. It also implies that A. Carlson's insistence on bipolar flow in the cusps cannot exist if the system works.
To error is human... and I'm very human.