1. Introduction
The National Ignition Facility (NIP) under construction at the Lawrence Livermore National Laboratory (LLNL) will be a U. S. Department of Energy and National Nuclear Security Administration (NNSA) national center to study inertial confinement fusion and the physics of extreme energy densities and pressures. It will be a vital part of the NNSA Stockpile Stewardship Program (SSP), which ensures the reliability and safety of U. S. nuclear weapons without full scale underground nuclear testing. The SSP will achieve this through a combination of above ground test facilities and powerful computer simulations using NNSA's Accelerated Scientific Computing Initiative (ASCI). In NIF up to 192 extremely powerful laser beams will compress small fusion targets to conditions where they will ignite and burn, liberating more energy than is required to initiate the fusion reactions. NIF experiments will allow the study of physical processes at temperatures approaching 100 million K and 100 billion times atmospheric pressure. These conditions exist naturally only in the interior of stars and in nuclear weapons explosions.