Nuclear fusion is a process in which two or more atomic nuclei combine to form a heavier nucleus, releasing a large amount of energy in the process. This is the same process that powers the sun and other stars.
Nuclear fusion has the potential to provide a nearly limitless source of clean energy. It produces no greenhouse gases, no long-term radioactive waste, and no risk of nuclear accidents. It also uses widely available sources of fuel, such as hydrogen isotopes.
While significant progress has been made in understanding and controlling the process of nuclear fusion, it has not yet been achieved in a sustained and controlled manner on Earth. Many research facilities, such as the Joint European Torus and the International Thermonuclear Experimental Reactor, are working towards this goal.
Nuclear fusion involves combining atomic nuclei, while nuclear fission involves splitting them apart. Fusion produces much more energy per unit mass than fission, and does not produce long-term radioactive waste.
The main challenge of achieving sustainable nuclear fusion is creating and sustaining the extreme conditions necessary for fusion to occur, including extremely high temperatures and pressures. Another challenge is finding materials that can withstand these conditions. Additionally, the cost of building and maintaining fusion facilities is currently very high.