Cost-effective containment of unmagnetized argon plasma using a magnetic bucket and a helicon source

We demonstrate highly-ionized and unmagnetized plasma production in the~low-power Compact HElicon for Waves and Instabilities Experiment (CHEWIE) at~West Virginia University. To achieve this, the argon helicon plasma is injected into a multidipole-confined expansion chamber. Using Langmuir probes~and optical emission spectroscopy, we calculate ionization fractions in the~unmagnetized volume as a function of input power and fill pressures.~Finally, we investigate the ionization efficiency power scaling to determine~if helicons are cost-efficient plasma sources for larger highly-ionized,~unmagnetized plasma experiments.