Important issues in high-current plasma experiments of the Z-pinch type

This paper is based on an invited lecture given at the 10th International Workshop and Summer School "Towards Fusion Energy", which was held in Kudowa Zdroj, Poland, on June 12-18, 2011. A concise review is presented of the known experimental results on various plasma Z-pinch experiments supplied by high-voltage and high-current pulsed power generators. The most important issues and the most valuable results in this domain are highlighted. A broad class of various Z-pinches is considered, including simple inter-electrode discharges, single exploding wires, so-called X-pinches, cylindrical wire-array Z-pinches, radial wire-array discharges, conical wire-array experiments, and gas-puffed Z-pinches. Non-cylindrical Z-pinch discharges (often called plasma focus experiments) are also briefly characterized. The most important characteristics of each category of experiments are outlined. Particular attention is paid to fusion-oriented high-power Z-pinch experiments and the problems encountered in experiments with various sophisticated fusion targets. The main issues in the described Z-pinch experiments are identified. Finally, new trends in the dense Z-pinch research are described.