| AVS 62nd International Symposium & Exhibition | |
| Plasma Science and Technology | Monday Sessions |
| Session PS-MoA |
| Session: | Plasma Diagnostics, Sensors and Control I |
| Presenter: | John Poulose, The University of Texas at Dallas |
| Authors: | J. Poulose, The University of Texas at Dallas L.J. Overzet, The University of Texas at Dallas S. Shannon, North Carolina State University D. Coumou, MKS Instruments M.J. Goeckner, The University of Texas at Dallas |
| Correspondent: | Click to Email |
Pulsed plasma provides a method to ‘independently' control ion and neutral fluxes. Temporal and spatial evolutions of the pulsed plasmas have been studied to provide a better understanding of transitory behavior in such systems. The optical emission intensities (OEIs) of various spectral lines from pulsed plasmas through Ar, O2, N2, CF4 gases and CF4/O2/Ar gas mixtures have been collected. The OEIs measured from CF4/O2/Ar gas mixtures show an axial oscillation of intensity with an approximate speed of 106 cm per second. This oscillation starts at the plasma strike and dampens to the background during the first 10 µs in 1 kHz pulse frequencies or lower. Radio frequency voltage and current measurements show changes over similar time periods. The transient reactance has been observed to correspond to the sheath formation in the OEI studies. Measured current and voltage frequencies have been observed to shift/pull by as much as 400 kHz during the initial turn on phase. The amount of the frequency pull is dependent on gas composition, electrode gap, pressure, and pulse properties. This shift occurs as a reaction to the plasma formation, specifically, the sheath development. We will present these results and the effects of other parameters on the transitory behavior of pulsed discharges.