INERTIAL CONFINEMENT FUSION IGNITION CRITERIA, CRITICAL PROFILES, ANDBURN WAVE-PROPAGATION USING SELF-SIMILAR SOLUTIONS

The ignition conditions, under which a thermonuclear burn wave propaga tes from an initial hot spot, and the characteristics of the propagati ng burn wave are investigated using a set of self-similar solutions. A lthough the self-similar solutions exist only for external density pro file that decreases as rho(out)(proportional to)r(-1), they are shown to provide natural ignition criteria and critical profiles for more ge neral density profiles. The concept of working lines (WLs), attractors of trajectories in the rho R - T plane of propagating burn waves, is introduced for density profiles p(out)proportional to r(-omega). The W Ls are found to be close and almost parallel to the ignition line (IL) . The distance of the WLs from the IL is given analytically and shown to depend on all the physical processes involved. The spatial profiles of a burn wave propagating along the WLs an shown to be closely relat ed to the self-similar critical profiles. (C) 1997 American Institute of Physics.