Fusion power is the generation of energy by nuclear fusion. Fusion reactions are high energy reactions in which two lighter atomic nuclei fuse to form a heavier nucleus. When they combine, some of the mass is converted into energy in accordance with the formula . This major area of plasma physics research is concerned with harnessing this reaction as a source of large scale sustainable energy. There is no question of fusion's scientific feasibility, since stellar nucleosynthesis is the process in which stars transmute matter into energy emitted as radiation.