If the overpressure created by the heating is sufficiently large, a hydrodynamic shock wave is formed and initiated the combustion of the nuclear fuel by a compressive heating. This self-sustained combustion is called detonation. In a general way, the detonations are propagated in a supersonic way of such way that the material is burned without to have had the time of expandre. The fuel is thus flaring entirely, forming only elements of the family of iron.