"There are three boxes we need to tick, in order to overcome this repulsion I mentioned before and get the nuclei very close. And this is not an easy feat. We need high temperature (think a hundred million degrees), high density (have a lot of these nuclei in a very small space), and keep the nuclei in that small space long enough for them to “react”. "<p>High temperatures are usually used because the nuclei must have a lot of force to counter that of the liked charged partner. The most obvious way to do this is with heating the plasma because individual particles, when they collide head on, can have the combined momentum to plow their way together.<p>But Philo T Farnsworth found a clever way to get them close with electrostatic forces. If it weren't for those darned wires.<p>With millions of degrees that plasma viciously expands. An even more incredible contraction force must be used to keep this together long enough for "interesting results". This is done with inertial confinement like the Hbomb or emulations of it. Magnetic confinement merely slows the expansion, but it must at some point touch the walls.<p>Actually, heat is not wanted. You only need to get the nuclei close enough that they quantum tunnel to each other to relieve their own stress in their environment. 2 Dueterons spread farther than helium3 does. Think of it like phase changes in condensed matter. Except we don't care at all about electrons, simply move them somewhere that the fuel ions wish to congregate at. Fortunately this can be a single point, as charges are concentrated on pointy things, as Faraday found in his experiments. The other side is full of the fuel ions. They don't have to be hot but warming them a little in an environment that is under 770 giga-pascals of pressure might be enough to moderate a nuclear combination process. It isn't hard to create two chambers in a crystal and make them undergo reductions or oxidations to free ions or electrons (tragically this happens with lithium ion batteries all the time). If they are surrounded in an environment that is very hard, very good dielectric strength, ions or electrons can be freed with no where to go. This is known as a meta-stable state and many crystal patterns exhibit this. The best dielectric known is diamond and it's also the hardest and has a ton of other helpful properties. If diamond couldn't do this, then nothing can. A mad genius with money and time would not have to go further than it to rule it out completely.<p>Say my fancy idea doesn't work, if colliding macro projectiles is something useful to the author have they tried something like levitating pyrolytic carbon and propelling it with laser ablation? It could be done in a loop if part of the magnet can de-energize fast enough to allow the tiny block of carbon to escape.<p>The plan they have seems very Wile E. Coyote to me but fun and cool. I hope they succeed.