Requirements For Fusion

Before fusion can occur an energy barrier has to be overcome. This energy barrier is created by the repulsive electrostatic force between the protons. At large distances the nuclei repel eachother because of the like charges from the positively charged protons in each of the nuclei. However, nuclear fusion is possible because of the strong nuclear force, which at close distances is stronger than the electrostatic force.

Also because of the repulsion from the protons high temperature and pressure have to be applied. Fusion reactors have to be about 100 degrees Kelvin. Hydrogen turns to a plasma (hot, electrically charged gas) at that high of a temperature. By using microwaves, lazers, and ion particles, high temperatures are achieved. Inorder for atoms to fuse together they need to be extremely close and magnetic feilds, lasers, or ion beams are used to apply large amounts of pressure. The controlling of such high temperature, pressure, and plasma have created science and engineer challenges.