Experimental observation of the hot electron equilibrium in a minimum-B mirror plasma

(12.06. – 18.06.2017

PHYSICS OF MULTIPLY CHARGED OXYGEN IN THE CONSTANCE B QUADRUPOLE MIRROR

Detailed experimental measurements of multiply-chargered ion densities, endloss currents,and temperatures have been made in a single cell quadrupole mirror. The purpose of these experiments is to determine the confinement physics of ions over a range of charge states in an ECR ion source. The parallel ion confinement times agree well with a theoretical model including Pastukhov and flow confinement for a potential dip of ϕi/Ti ~ 1. The ion endloss currents were found to be up to 50% hollow. Radial transport of ions'was found to be important in limiting the extraction of high charge state ions. In addition, by heating O4+ with ion cyclotron resonance heating we were able to increase its extracted current in the plasma center by 25%