[johnbcoughlin]

I doubt they have achieved any fusion reactions. They don't state any numbers on density or temperature so it's impossible to know. But in general plasma is never "caused by" fusion. Creating a plasma is quite easy compared to getting it hot and dense enough to fuse.

[__MatrixMan__]

I'm musing about the phrase:

> plasma is never "caused by" fusion

Which do you suppose comes first in a gravitational confinement scenario, plasma or fusion? It sorta seems like a chicken/egg scenario. I mean you gotta get those electrons out of the way, but where does he heat come from to do that, if not fusion?

[willis936]

Definitely plasma. Look at star formation in nebulae. Most of the hydrogen in them are in glow mode plasma. It takes a very small amount of energy to ionize plasma and a a huge amount to fuse it. So when stars are forming they might start as cold hydrogen, but they get progressively warmer and more dense until they ionize, then get even warmer and more dense, until they're burning.

https://en.wikipedia.org/wiki/Star_formation

[cyberax]

They likely can have some fusion reactions (if they use fusible fuel, like D-D). Fusion is not that hard to achieve, you can do that on a table-top scale (Farnsworth Fusion).