Speaker
Description
See the full abstract here:
http://ocs.ciemat.es/EPS2019ABS/pdf/P1.3011.pdf
High-density compressed plasma flows have many applications in the field of plasma-surface interaction [1, 2]. Additionally, magnetoplasma compressors (MPCs) are among the most commonly investigated types of possible technological sources of extreme ultraviolet (EUV) radiation [3]. Previous experimental findings have revealed that electromagnetic force distributions, as well as initial concentrations of working gases, interrelate closely with the main parameters of the compressed plasma stream, such as density and temperature, and, as a result, affect a spatial position of a compression zone. Nonetheless, a comprehensive study on the characteristics of spatial distributions of the electromagnetic forces and the output currents under various initial experimental conditions is still needful.
We have investigated the distinctive features of the MPC plasma flows for three gases at different initial pressures: argon (133.3 Pa), nitrogen (40 Pa and 80 Pa), and helium (266.6 Pa and 1.33 kPa). The experiments were carried out under the mode of operation with residual gas in the MPC facility. Spatial structures of the output currents (including fun-like configurations and induced toroidal current vortexes) have been plotted by using the data retrieved from the magnetic probe measurements. Overall, the results have clearly shown that the peculiarities of the compressive structures where the electromagnetic forces are directed mainly to the near-axis region or/and opposite to the plasma flow are intrinsically related to a particular operational mode. The plasma velocity and the density measurements, which illustrate dynamics of plasma stream deceleration and formation of compression zone with average electron density above 10^18 cm^-3, are in agreement with obtained distributions of the local electromagnetic forces.
[1] M.S. Ladygina et al. 2016 Phys.Scr. 91 (2016) 074006
[2] D.G. Solyakov et al. 2013 Plasma Phys. Rep. 39 986-92 [3] I.E. Garkusha et al. 2014 Phys. Scr. 161 014037
