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David Kirtley

๐Ÿ‘ค Speaker
See mentions of this person in podcasts
1578 total appearances

Appearances Over Time

Podcast Appearances

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

And what that does is magnetic field is electromagnetic current and current running in a wire.

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

And what that does is pushes current back in the wire.

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

And so the plasma itself now pushes back on the magnetic field, pushing electrical current out of the system and recharging the capacitors where we started this whole process.

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

Yeah, I like the analogy of

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

the match and the campfire.

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

And I hear that a lot in fusion where, um, a lot of what steady fusion think a stellarator or tokamak is attempting to do is take a little bit of fuel that match and then add heat, um,

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

to ignite that match and then put it with enough fuel and in the right conditions and hold on to it for a long time that it grows into a campfire, even if they do a good job of bonfires, creating a tremendous amount of energy in that steady system, burning fuel in the same place, generating some ash, generating a lot of heat

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

in that reaction.

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

And in a traditional, in a tokamak or a stellarator, that's a lot of what you're doing is you're holding on to the heat as much as possible to keep that reaction going.

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

And in that, the optimal fuel is called deuterium and tritium, where you have deuterium

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

is a heavy isotope of hydrogen where you have an extra neutron.

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

And tritium is a very rare form of hydrogen that's an unstable form.

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

It's so rare, it's hard to get, where it has two neutrons and a proton.

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

And when you fuse those together at very high temperatures, at very high densities, or high enough densities and very high temperatures, they make helium, which is a charged particle, which stays inside the campfire, inside the tokamak,

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

continuing to heat it and stoke the flames.

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

And it makes a neutron, which leaves the system because it's uncharged.

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

It has no charge.

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

And in that system, it's actually ideal.

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

It's really great because in a campfire, you have this reaction going and you want to get the energy out of it.

Lex Fridman Podcast
#485 โ€“ David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

You want to use it.