4 - Fusion reactors in space

Summary

FUSION

It is often argued that man's growing energy needs will be met if he succeeds in making fusion reactors. In a fusion reactor, energy is generated by fusing together light atomic nuclei and converting them into heavier ones. The primary fuel for such a fusion reactor on the Earth would be heavy hydrogen, whose technical name is deuterium. Through nuclear fusion, two nuclei of deuterium are brought together and converted to the heavier nucleus of helium, and in this process nuclear energy is released.

The following is the recipe for a fusion reactor. First, heat a small quantity of the fusion fuel, deuterium, above its ignition point – to a temperature of some 100 million degrees Celsius. Second, maintain this fuel in a heated condition long enough for fusion to occur. When this happens, the energy that is released exceeds the heat input, and the reactor can start functioning on its own. The third and final part of the operation involves the conversion of the excess energy to a useful form, such as electricity.

The primary fuel for this process, the heavy hydrogen, is chemically similar to but a rarer version of the commonly known hydrogen. An atom of ordinary hydrogen is made up of a charged electrical particle called the proton at the nucleus with a negatively charged particle, the electron, going round it. The nucleus of heavy hydrogen carries an additional particle called the neutron in its nucleus. The neutron has no electric charge so the total charge of the nucleus of heavy hydrogen is the same as that of ordinary hydrogen.