For equal amounts of fuel mass, the energy from fusion is about a million times greater than that released from a chemical reaction, such as the burning of fossil fuels. For fusion to occur, several conditions must be met. Thus, the fuel's temperature must be roughly 100 million degrees Celsius and enough fuel must be held together long enough for the nuclei to collide and fuse. In our solid-state laser systems, a small pulse of infrared laser light is amplified again and again through many laser stages until it reaches high power. The infrared light is then converted to ultraviolet light and focused onto the fusion target.
X rays heat the outer surface of the capsule, for an instant, to about a million degrees.