Studies of Plasma Confinement and Stability in a Gas Dynamic Trap: Results of 2016 - 2018

Paper presents a brief overview of the studies carried out in 2016-2018 at the Gas Dynamic Trap device at the Budker Institute. These studies were focused on the experimental substantiation of a new version of the Gas Dynamic Multi-mirror Trap project, which is aimed at developing the key technologies needed to implement a number of thermonuclear applications of linear magnetic traps. The paper reviews the work aimed at stable plasma confinement under auxiliary ECR heating. We showed that a value of on-axis electron temperature up to 450 eV at plasma density 1.2 x 10(19) m(-3) can be supported steadily. Studies on processes in expanders, which determine the axial thermal conductivity of the plasma, showed that the profile of the electric potential in the expander corresponds to a theory that gives favorable predictions regarding the thermal insulation properties of the expander. It was shown that the density of neutral gas in the expander in the range up to 10(20) m(-3) does not have a significant effect on energy confinement in the trap, despite an estimate of the critical density of 10(18) m(-3). (C) 2019 The Japan Society of Plasma Science and Nuclear Fusion Research