Yep! This is one reason why I argue we should do lowish power density fusion, in space, using the vacuum of space. There’s a nice set of existence proofs, and the gentle magnetic fields do a much better job of confining energyhttps://twitter.com/michael_nielsen/status/1223291031338115072 …
with all of that, you end up with magnetic confinement for extremely low mass. heat the plasma with lasers (cyclotron heating?) or RF and use a cathode ray / accelerator to neutralize to create thrust.