Fast ion production by suprathermal electrons in laser fusion plasmas

Abstract

The acceleration of ions by two isothermal species of electrons, thermal and suprathermal, in a laser-fusion plasma is investigated. The disassembly of an initially stationary plasma slab, including charge separation effects, is described. Before the rarefaction wave has penetrated appreciably into the slab, an interior Debye sheath which separates the suprathermal and thermal electrons, as well as an exterior sheath at the ion-vacuum interface is found. As the rarefaction approaches the center of the slab, the dynamics is modified due to the conservation of species number and total energy. The energetics of the long-time evolution is described by a quasi-neutral similarity solution appropriate to finite two-electron species systems.