I'm slightly confused here. I know that once nucleons fuse to make the nucleus or vice versa there is a change in energy as shown in the mass-energy equation.
What I don't understand is which part of this is the usable energy?
Is it that anything over the binding energy is usable energy? e.g. if the binding energy was 33MeV and 35MeV was released during the fission, then 2MeV would be the excess usable energy?
And also, when the term "energy released" is used in terms of fission or fusion, is it referring to the binding energy, the excess usable energy or both?
Sorry one more question, in fusion what is it that does work to fuse nucleons? it's heat right?
thanks in advance!