The D-D reaction is less energetic and produces a neutron, and the D-He3 reaction doesn't produce a neutron. The combined reaction would release about five percent of its total energy as neutron radiation. The neutrons from D-D are about as energetic as fission neutrons, rather than the extremely high energy of D-T fusion neutrons.

They'll never run out of fuel; there's enough deuterium in your morning shower to provide all your energy needs for a year. But the need to breed He3 will put a limit on how fast they can possibly scale up. It could be that manufacturing will be slower than that anyway though.

Of those, only the protons have an electric charge you could use in any form of generator… but I’m not aware of any form of reaction that predominantly creates protium. The fragments are also charged, but the implication that you’re using fission means they’re in the middle of a block of uranium and won’t keep their speed for long.

The others ignore electromagnetic fields for the most part, and will fly around until they smash into something and go goooong like the world’s smallest bell. Or smash through something, perhaps; it’s a chain reaction after all.

This mostly just makes other stuff move about. Repeat a few dozen times, and you’ve got heat.

However, the alpha decay of some product of the fission reactions does not change the total charge of the fissile material, because the emission of a helium nucleus with a double positive elementary charge leaves a heavy nucleus with a diminished nuclear charge, by those two elementary charges.

Only when the alpha decay happens to occur close to the surface of the material, the positive helium nuclei may escape from it and they could land on a collecting electrode, making that electrode positively charged and leaving the fissile core negatively charged. However such a process would extract only a negligible part of the energy produced by fission. Even if the alpha extraction could be enhanced somehow, the decay energy of the fission products is small in comparison with the energy produced by the initial fission of the uranium nuclei. Extracting directly from the fissile material the nuclei generated by fission would be much more difficult than extracting the helium nuclei.

The Darpa project may succeed to stimulate the creation of some electric generators that could deliver additional energy from a fission reactor, by direct electric charge separation, but that would remain a small part of the total fission energy, most of which will still have to be extracted through thermal methods, like today.

  2D  + 3He → 4He + 1p  + 18.3 MeV
  3He + 3He → 4He + 2 1p  + 12.86 MeV

Yep, it's a big nuclear powered boiler. Boil water, get the steam, spin the turbin, cool the water, repeat.

Gravity batteries could be a thing but pumped water is the best version of that system, in this case we don't boil the water tho

Is the direct energy capture part also harder for glowy fusion gas than scary fission rocks?

So they have a simple way to extract electricity directly. They squeeze the plasma with a magnetic field from a copper coil, then there's an explosion of charged particles, which pushes back against the magnetic field and causes electricity to flow in the coil.

The main issue with D-He3 is that it's more difficult.

By analogy, compare Concentrated Solar Power versus Photovoltaics.

They're actually pretty much on schedule, once you account for the several years it took them to get the necessary funding.

> In 2023, we will end operations on Trenta, our 6th fusion prototype… Our results suggest that Trenta is currently the best performing privately-funded fusion machine in the world. After these last weeks of plasma operations under vacuum, we will retire Trenta and move all focus to Polaris, our 7th fusion prototype, expected to demonstrate net electricity in 2024.

So, they have 143 days left to make good on their current timeline, I guess.

So, indeed, so far they failed at energy, and they've only succeeded at fusion in the same way and at the same scale that university labs have.

So I guess you're right: they're not even any kind of company at the moment. They don't sell anything. They're an R&D lab.

Think of it as a conspicuous luxury handbag for weird finance/tech bros. "Oh yeah? Well MY investments are going to save the world!!!"