2 ms·
As a practical matter most of the byproducts of antimatter annihilation aren't amenable to being directed out the rear of a spacecraft by a nozzle, magnetic or
by Symmetry 10y ago
As a practical matter most of the byproducts of antimatter annihilation aren't amenable to being directed out the rear of a spacecraft by a nozzle, magnetic or otherwise. So the maximum theoretical efficiency is possibly better with advanced fusion drives than with antimatter.