Energy positive? That made me laugh. Making antimatter is more energy negative than building a 747 out of gold. They burn through enough power to light a town in order to capture a literal handful of antimater particles.
In a rocket it would not be useful. It has the energy but would emit it as all sorts of highly penetrating radiation rather than hot gas for a rocket nozzle to turn into thrust.
One particle has enough energy to, maybe, if it hit a speck of dust it might result in a perceptible twitch of that speck of dust... if you were watching the spec under a good optical microscope.
In a rocket it would not be useful. It has the energy but would emit it as all sorts of highly penetrating radiation rather than hot gas for a rocket nozzle to turn into thrust.
One particle has enough energy to, maybe, if it hit a speck of dust it might result in a perceptible twitch of that speck of dust... if you were watching the spec under a good optical microscope.