Application of Liquid Metal Droplets in Tokamaks and Plasma Devices (a Review)

Record-long plasma confinement times in tokamaks could be attained using new methods of erosion protection of plasma-facing materials (including the use of liquid metals). This article reviews the publications on the application of liquid metal droplets in the form of droplet screens to improve the plasma confinement and to protect the vacuum chamber walls from thermal loads. The variants of designs of devices ensuring the injection of droplets into the volume occupied by the plasma and the main results are considered. Analysis of parameters of liquid metals being injected indicates the possibility of controlling the flow parameters such as the droplet size and velocity. The results of investigations show the possibility of using metals in the chamber without violating vacuum conditions and contamination of the plasma. Further experiments are required to substantiate the application of liquid metal droplet screens in plasma devices.