What is Nuclear Fusion?
Nuclear fusion is the most powerful source of energy known to man. It is the process that creates the heat of the sun and the stars. Unlike nuclear fission, nuclear fusion does not involve high levels of radioactivity. We believe that if we could control the process of nuclear fusion, we would have a clean, safe and virtually unlimited energy source. Releasing Energy from Fusion If two hydrogen isotopes – deuterium and tritium – are fused together, the act of fusion releases helium, which is a harmless gas; a neutron; and, crucially, a lot of energy. This is what happens in the hydrogen bomb, but here it is an uncontrolled reaction that results in explosion. Various ways of initiating a process of controlled fusion have been investigated; however, one recurring problem is the huge amount of power necessary to trigger fusion. The reason so much power is needed is that every hydrogen atom naturally repels every other hydrogen atom. Their nuclei all contain protons with a positive charge,
Nuclear fusion can, in some senses, be considered to be the opposite of fusion. Instead of splitting heavy nuclei, in the fusion process light nuclei are forced to combine to form a larger nucleus. Again, the binding characteristics of the original nuclei and the resultant nucleus (and of course the mass-energy relation) ensure that energy is released during the fusion process. The fusion process can only occur at very high temperatures, because of the need to force nuclei with like charges together. The fusion process occurs in many forms in the sun (where the temperatures are high enough for fusion to occur), and is the basic principle on which the H-bomb operates.
