I was reading the top answer on this page and I didn't quite understand if the author (presuming the answer is correct) meant a) that fusion was always better, or b) that once we figure out fusion we can/should use it to power the process of making antimatter but then use the antimatter for some purpose other than generating electricity.
I know that we do not yet have full-time working break-even fusion reactors (even though experiments have been done that go in that direction) and that there are no large amounts of antimatter around us for us to use so we have to generate it, and that there are problems associated with storing it safely and so on. Because of this, if we want to generate it, we have to put in the full amount of energy that we could theoretically get out of it in order to satisfy e=mc2, and that not only would none of those processes would be 100% efficient, but that we couldn't effectively use all of the annihilation products for electricity generation.
Considering that fusion fuel is already available to us, can antimatter ever actually be superior to fusion in terms of being used to generate electricity? In other words, within the boundaries of what we know about physics today, is trying to develop the most efficient form of fusion (possibly combining a fission cycle) the best way to go about it? Or do physicists believe that if we can bypass engineering issues, in principle, antimatter electricity generation could one day be superior (more useful energy out for what we put in)?
I also ask this based on this question and this question.
Best Answer
If you look at our observable universe, there is no bulk antimatter. Physicists discovered antimatter experimentally, and the present standard model of physics posits the existence of antimatter.
BUT to generate antimatter , one has to spend at least the energy of generating twice the mass, particle and antiparticle, and this can only happen in an accelerator which will have to be fed with a lot more extra energy so that the beams, colliding or hitting targets, can generate the particle antiparticle pair. They come in pairs because of conservations laws, lepton number for electrons and positrons, baryon number for protons and antiprotons.
Fusion utilizes the existing nuclear state taking advantage of the binding energy curve, rearanging existing particles not creating new ones.
With this in mind, :
No.
In terms of energy in energy out yes, it is much more efficient.
Not for cost, creating antiparticles is very costly.
For usefulness in space travel, if antimatter could be stored, which I find doubtful, it might be efficient. At the moment though magnetic fields are needed to store antimatter plasma, and those are also energy eaters. All in all fusion wins in the energy balance sheet.