Inertial Confinement Fusion with Tetrahedral Hohlraums at OMEGA

Abstract

Indirect-drive inertial confinement fusion will require for ignition a highly symmetric x-ray flux around the capsule. To this end, the ``tetrahedral hohlraum,'' spherical in shape with four laser entrance holes located at the vertices of a tetrahedron, has been proposed. The first experimental test of this concept, using the OMEGA laser, is reported here. Drive symmetry was probed using capsule implosion symmetries, which varied qualitatively as expected with hohlraum dimensions. Modeling of the experiments gives time-averaged flux asymmetries as low as $1%$ rms over a 2.2-ns laser pulse.