Usually you are trying to catch neutrons in a lithium blanket, and using the fission products to extract energy. At least that is what they are doing at ITER. T

Usually you are trying to catch neutrons in a lithium blanket, and using the fission products to extract energy. At least that is what they are doing at ITER. The electromagnetic energy goes back into the plasma and helps with keeping things hot. The energy extraction is one of the biggest challenges with sustained fusion.