  Radio Frequency (RF) driven helicon plasma sources are commonly used for
their ability to produce high-density argon plasmas (n > 10^19/m^3) at
relatively moderate powers (typical RF power < 2 kW). Typical electron
temperatures are < 10 eV and typical ion temperatures are < 0.6 eV. A newly
designed helicon antenna assembly (with concentric, double-layered, fully
liquid-cooled RF-transparent windows) operates in steady-state at RF powers up
to 10 kW. We report on the dependence of argon plasma density, electron
temperature and ion temperature on RF power. At 10 kW, ion temperatures > 2 eV
in argon plasmas are measured with laser induced fluorescence, which is
consistent with a simple volume averaged 0-D power balance model. 1-D Monte
Carlo simulations of the neutral density profile for these plasma conditions
show strong neutral depletion near the core and predict neutral temperatures
well above room temperatures. The plasmas created in this high-power helicon
source (when light ions are employed) are ideally suited for fusion divertor
plasma-material interaction studies and negative ion production for neutral
beams.
