The working of hydrogen bomb is based on nuclear fusion. But for the process of nuclear fusion, a very high temperature (≈107K) and a very high pressure is required, hence to construct a hydrogen bomb, first atom bomb is constructed. The atom bomb is then covered from all sides by an enclosure of a compound of heavy hydrogen (deuteron) such as lithium hydride. First the atom bomb is exploded which produces such a high temperature and pressure that deuteron nuclei get fused and a huge amount of energy is released.