The United Nations projects an increasing population and increasing energy demands. In order to meet future needs, long-term sustainable energy sources are required. Ideally future energy sources will comprise a mix of energy technologies - solar, renewables, advanced nuclear fission and fusion.
Fusion requires energetic collisions of very light elements, usually hydrogen isotopes, resulting in a nuclear reaction that leads to more stable helium nuclei and other byproducts. A net loss of mass results, yielding free energy as given by Einstein's famous equation.
There are three basic confinement mechanisms required for fusion reactions: gravitational, inertial, and magnetic. The Tokamak Fusion Test Reactor (TFTR) at Princeton(below left) uses magnetic confinement.
Plasma radiation within the Princeton Tokamak during operation.
Both inertial and magnetic confinement fusion research have focused on confinement and heating processes with dramatic results. The next stage of operating power reactors will produce about 1 GW of power and operate at
120 million degrees Kelvin. [from Contemporary Physics Education Project chart]
