David Kirtley

And what those programs were, were a linear topology, because we knew how to build these magnets.

It's called a solenoid, where you take a series of electric coils, you run electrical current through them, that generates a magnetic field.

Great, so you have a magnetic field.

Now you add your fusion particles, okay?

So you've added fusion particles to this solenoid.

Here's the challenge.

Those particles, as they're sitting in that magnetic field in this nice magnet, escape.

They leave out the ends because there's nothing holding them in.

Great.

So that makes sense.

And so that doesn't work.

Okay.

So then the next approach is say, well, one branch of fusion said, okay, well, to solve that, why don't we take this solenoid and bend it around?

Let's just make it a big donut.

So as they're escaping, they go around and around in a circle.

Great.

That's a great approach.

And so one branch of fusion went down that direction.

And that became, that evolved into the stellarator and the tokamak, different ways of taking those solenoids and wrapping them around so that the plasmas go around and around in that magnetic field and those charged particles are held long enough that fusion happens.

But there's a different way to do it.