One-dimensional planar hydrodynamic theory of shock ignition

A one-dimensional planar compressible-piston-like model is used to investigate the basic physics behind shock-ignition inertial confinement fusion implosions. We discuss the theoretical limit set by rarefaction waves on the maximum hot-spot pressure achievable through conventional compression. Three ignitor shock techniques are presented to mitigate the effects of rarefaction waves, enhance the stagnation hot-spot pressure, and improve the ignition conditions. Elimination of rarefaction waves can lead to an similar to 80% increase in peak implosion pressures, while implosions augmented with ignitor shocks are shown to increase the peak pressures by a factor of similar to 4. These techniques are then discussed and the optimal energy ratio between the initial shell kinetic energy and the ignitor pulse energy is given. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3619827]