Reverse of a particle accelerator. The alpha particles (positively charged) are generated already moving fast, and are brought to a halt by a bucking high positive voltage. The output in the external circuit is megavolts at a low electron current, the flow required to neutralize the alpha particles. The neutral helium is then drawn off by vacuum pumps.
Got it. In my college days I worked on a research project relating to MHD. Great idea and based upon some validated theory(ies) but very difficult to get the particles to follow the path we wanted them to.
https://en.wikipedia.org/wiki/Magnetohydrodynamics
I hope this new approach works, but fusion always seems to be a pipe dream - pushing an area we may not completely have a full grasp of.