The past, present, and future of Z pinches

The Z pinch is enjoying a renaissance as the world's most powerful yet effi cient soft x-ray source which can energize large volume hohlraums for indir ectly driven inertial confinement fusion. It has the advantages of being ef ficient and having high energy and power density. Its early history will be traced from the 18th century to the present day. The most notable feature of the Z pinch is its instability. The various regimes of stability analysi s will be reviewed, including resistive and finite ion Larmor radius effect s. Work in the last 10 years on single fibres, especially of cryogenic deut erium, gave neutrons that were of the same origin, namely, beam-plasma inte ractions, as reported by Kurchatov. The renaissance has come about through the implosion of arrays of fine wires. Research at Sandia National Laborato ry has shown that by using more and finer wires, the x-ray radiation emitte d at stagnation increased in power and decreased in pulse width. The unders tanding of these results has been advanced considerably by theory, simulati on and smaller-scale, well diagnosed experiments showing the early uncorrel ated m=0 instabilities on each wire, the inward jetting of plasma to the ax is, the global Rayleigh-Taylor instability and the mitigating effect of nes ted arrays. (C) 2000 American Institute of Physics. [S1070-664X(00)97705-X] .