Imploding Liner Compression of Plasma: Concepts and Issues

Several plasma targets have been proposed for compression by imploding liners, ranging from magnetically-confined to wall-supported concepts. In all cases, a critical issue remains one of preventing the high atomic-number material of the liner from penetrating the plasma and countering the gain in plasma temperature sought by compression. Two factors foster development of such deleterious penetration: the creation of a liquid/vapor layer at the liner surface at high magnetic fields, and disruption of this layer by Rayleigh-Taylor instability in the final stages of plasma compression. Within a general consideration of issues of liner compression of plasma, we discuss reactor cost optimization by use of plasma at pressures intermediate between the values of conventional magnetically-or inertially-confined fusion concepts. We also describe the development of an equilibrium layer of vapor adjacent to the liner surface at high magnetic fields, the instability of such a thin layer, and the consequences of liner deceleration and rebound for reactor concepts and research progress.