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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

They don't have magnetic fields, but very high pressure.

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

And then in stellarators and tokamaks, your goal is very long tau, but you'll have much lower density.

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

And you can't really go too much in temperature, but they'll have much lower density.

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

And so where we live in the post-magnetic or the magneto-inertial fusion is in the middle, is in extremely high magnetic fields, increasing pressure as much as you can, and then keeping them around long enough.

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

And so that gets to the tau, that gets to that energy confinement lifetime, and also it gets to stability.

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

And so this is the thing that this field reverse configuration, which has showed that we can build, that these plasmas can last for hundreds or thousands of times, the basic theory has shown that now you can have long enough lifetimes.

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

So what that means is in a practical fusion system,

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

There are lifetimes of these high beta pulse systems between 100 microseconds and a few milliseconds, thousandths of a second.

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

And you hold on to it for a few thousandths of a second, you do fusion, and then you exhaust it.

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

And so the whole process in this is we start with a magnetic field that fills the full chamber.

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

you then inject fusion fuel.

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

You ionize it, superheating it now to an ice cold one million degrees, but hot enough that you have charged particles, you have plasmas.

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

You can then start increasing the magnetic field.

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

You form a field reverse configuration and then rapidly increase the magnetic field further, increasing from one to five to 10, 20 to even higher magnetic fields.

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

And as you do that, the plasma heats, you compress it, increasing the field and pressure.

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

Fusion is now happening.

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

New charged particles are being born inside this system with a tremendous amount of heat and energy, but in charged particles.

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

And this is where the beta really, really works in your advantage, is that just like

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

Magnetic pressure on the outside, magnetic pressure is NKT, compresses the fuel and increasing pressure and temperature.

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

When the pressure and temperature of the plasma increase, NKT increases, it pushes back on the magnetic field, increasing the magnetic field on the outside of the plasma.