Theoretical Determination of the Radiation Pressure Inside of the NIF Hohlraum

Abstract

The NIF facility was created to study fusion under controlled conditions. One hundred and ninety two of the world’s most powerful lasers are focused onto a very small gold cylindrical target. The high intensity laser heats up the gold hohlraum (target) to a high temperature and produces a photon gas. The high temperature allows the photon gas to be treated as a black body, and as such, produces a radiation pressure inside of the hohlraum which causes a deuterium-tritium pellet to implode and fuse into helium. Theory shows that a radiation pressure of between one and two megabar is sufficient to cause the D-T pellet to implode. Using black body temperature calculations from radiation incident on an object, the temperature of the photon gas inside of the hohlraum was found to be 115 MK. At this temperature, the radiation pressure inside of the hohlraum is 6.142 Mbar. This illustrates that the conditions created by the NIF facility are conducive for fusion.