Ion acceleration in Ar-Xe and Ar-He plasmas. I Electron energy distribution functions and ion composition

Electron energy distribution functions (eedf), ion production, and ion composition are studied in Ar-Xe and Ar-He expanding helicon plasmas It was found that under the conditions of constant total flow rate, Xe, in addition to Ar, changes the eedf from Maxwellian-like to Druyvesteyn-like with a shortening of the high energy tail at similar to 15 eV The electron temperature exponentially decreases from similar to 7 eV in pure Ar plasma to similar to 4 eV in pure Xe plasma Xenon ions dominate the ion population for Xe filling fractions greater than 10% The plasma density increases by similar to 15% with increasing Xe fraction For an Ar-He plasma, increasing the helium fraction increases the electron temperature from similar to 7 eV in pure Ar plasma to similar to 14 eV for a He filling fraction of 80% The plasma density drops by more than three orders of magnitude from 1 14 X 10(11) cm(-3) to 6 5 X 10(7) cm(-3) However, the inferred ion densities indicate that even at a helium fraction of 80%, argon ions significantly outnumber helium ions (C) 2010 American Institute of Physics [doi 10 1063/1 3505822]