A Plasma Donut

We know [The Action Lab] always has something hands-on. This time, the video shows a toroidal plasma demo and how it relates to nuclear fusion. Plasma has a high temperature, ….

Plasma has a high temperature, and if you use physical electrodes to excite the plasma, this high temperature tends to destroy the electrodes. But thanks to the relationship between electricity and magnetism, you can create plasma with an alternating magnetic field instead of physical electrodes. The actual practical device is a 10 MHz source with a coil and a low-pressure globe full of xenon gas.

Of course, the little tabletop demo isn’t strong enough to drive a fusion reaction. But if you scale it up and make some modifications, including using hydrogen, you get a tokamak reactor. The problem, of course, is that current reactors need more energy to operate than they produce.