He starts talking about the plasma around the 0:59:00 mark.
So I'm gonna play a video here. I wish I had some sound cause it kinda sounds really cool, but none the less. I'm going to explain. We have here electromagnetic pump on one side and on the other side these are the molten silver reservoirs. We are looking down through the dome, and so we have a view port there. And we have, it's in a vacuum chamber and we have the window that we can look into the cell. So we are looking right down into the cell. And what we are gonna do here is turn the pumping power up and then we are going to gradually turn on the ignition and you will see when these two streams hit they get electrical contact, we will put the ignition on, and nothing should happen. But you will see it will make a bright plasma and through the video at different points we will turn it off and you will see it can persist. By the end, we will turn it off and you can't tell the difference whether it has power into it or not. Because in the auto mode. There's no one whose ever created a plasma that self sustains itself. And you'll see that. And this is at atmospheric pressure which is insane to have a plasma of this type at that high pressure.
The screen behind him states, "IGNITION OFF" at around 1:07:27 yet the plasma ball is still brilliantly bright. Later, it comes back on and goes back off with the plasma ball remaining.