Most fusion power systems assume they are doing that as neutrons. D-T fusion conveniently has the proportion of energy that gets lost from the plasma as KE of n

Most fusion power systems assume they are doing that as neutrons. D-T fusion conveniently has the proportion of energy that gets lost from the plasma as KE of neutrons be pretty close to the amount of energy that a conveniently sized fusion reactor can afford to remove from the plasma. Then you trap the neutrons with, for example, a lithium blanket, use them to breed more tritium, and produce energy with a turbine from the heating of the blanket.