ikanreed wrote: Well, I suppose that’s pretty reasonable. But, for example FoFu-1 is very sensitive to disruption. Imagine if you had tin whiskers on the electrodes, even very tiny ones.

Tin? Where would the tin come from? The electronics would have to be outside the vacuum chamber.

And even an FF space drive will have a vacuum chamber… as the fuel pressure has to rise to several torr before you can start it.

That it is space-based would just mean that you save on the cost and maintenance of a vacuum pump.

A plasma window should be able to allow the beam to exit the chamber into an exhaust assembly of some kind while maintaining chamber pressure.