that wasn't what I was complaining about.
there's plasma, and then there's plasma.
I *sincerely* doubt the engine replicates the conditions of a stellar core.
I googled 'Vasimir', and came out with this,The development of the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) was initiated in the late 1970s to address a critical requirement for fast, high-power interplanetary space transportation. Its high-power and electrodeless design arises from the use of radio frequency (RF) waves to create and accelerate plasma in a magnetic nozzle. While not being a fusion rocket, it nevertheless borrows heavily from that technology and takes advantage of the natural topology of open-ended magnetic systems." This would seem to indicate a plasma of ionized hydrogen or helium. The authors of the paper I've just quoted, Chang Diaz, F.R.; Squire, J.P.; Glover et al, admit that this is not quite close to fusion conditions. It may have been a leap by the reporter of the original article to assume so.