7. Plasma confinement

Just like a conventional power plant, a fusion power plant will use the energy released during fusion reaction to produce steam and then generate electricity by way of turbines and generators. But as noted in the above discussions, it is hard to harness the energy in a laboratory environment.

Each fusion reaction is characterized by a specific ignition temperature, which must be surpassed before the reaction can occur. In stars, which are made of plasma, fusion takes place because of immense gravitational forces and extreme temperatures. Trying to create similar conditions here on Earth has required fundamental advances in a number of fields, from quantum physics to materials science. Scientists and engineers have made enough progress over the past half century, especially since the 1990s, so that a fusion reactor able to generate more power than it takes to operate can be built. Supercomputing has helped enormously, allowing researchers to precisely model the behavior of plasma under different conditions.

One of the major requirements in the development of a fusion reactor is the actual realization of the ignition temperature of d-t reaction, which is 100 million degrees Celsius. Once all the conditions are realized, the challenge to contain and control the staggering levels of heat in the plasma is formidable. That is because the plasma must not only be heated to a temperature of at least 100 million degrees Celsius, but the energy must also be confined within the plasma without being carried to walls of the container for times long enough for the relatively infrequent fusion events to occur. Otherwise, the plasma will exchange energy with the walls, cool itself down, and melt the container.

Many techniques have been developed, but the two main experimental approaches that seem capable of doing this task are magnetic confinement and inertial confinement.
