David Kirtley

so that they can move at high velocity, over 100 million degrees, bring enough of them together, we call it density, enough of them together in a certain volume, so that you have reactions happening at a higher rate, and keep them together long enough that they are able to collide into each other and do fusion and release energy.

That's the fundamental core.

Now, how you do that, how you bring those particles together, how you hold them together long enough, there's a wide range of technologies that

as humans we've been exploring since the 1950s.

And I think about several main categories.

If you look at the fusion funding out there, government funding in the world, private funding actually has quite a different profile, which is an interesting thing to talk about.

But in public funding and federal funding in the United States, there's two mainline programs called inertial fusion and magnetic fusion.

And in inertial fusion, what you're trying to do is bring together and push together by a variety of means, physical means, those particles, you push them together.

The most common is called laser inertial fusion.

Our colleagues at the National Ignition Facility did this really well and made world records in the last few years for being able to demonstrate you can do this and do it at scale.

where you take very high power lasers and pulse them together to combine them to do fusion for a pulse for a very short period of time, nanoseconds, billionths of a second.

The other extreme, and you mentioned tokamaks and stellarators.

Stellarators are actually my favorite, so we'll talk about those.

Graduate student in fusion, the stellarator is the first thing you learn about because there's a mathematical solution for a stellarator that solves perfectly.

And you can write it out and you can solve it.

And analytically, it's very simple.

Building one is very hard.

And so it's taken humanity a number of decades to be able to build stellarators.

And we can do it now.

with the Wendelstein 7X that came online in the last few years being the premier stellarator in the world.