Atomic effects in the turbulent properties of microwave generated plasmas

Summary form only given, as follows. Microwave plasmas are generated in helium, neon, argon, krypton, and xenon at various microwave powers and neutral gas pressures. A floating Langmuir double probe is employed to diagnose plasma electron density and temperature. Bias voltage and current characteristic curves are analyzed for the determination of electron temperature and density for all five gases. Turbulence analysis is carried out by using time resolved neutral line emission data from these gases at a sampling rate of 100 MHz. Fourier spectra of emission fluctuations allow determinations of the total turbulent energy and the characteristic turbulent fluctuation frequency, which is also evidenced by the periodic motion in the phase space trajectory. The computations for chaotic dimension are also carried out for all five species. Systematic trends in the turbulent parameters show a dependence on atomic weight. These trends are consistent with observations of molecular influence on turbulent transport found in other plasmas and neutral gases and with current theoretical models.