Space and time resolved electric field measurements in helium and hydrogen RF-discharges

摘要: The sheath dynamics of helium and hydrogen RF-discharges at 13.56 MHz in the GEC reference cell are studied by laser spectroscopic electric field measurements. In case helium, Stark splitting n = 11 Rydberg state is measured LIF spectroscopy applied to metastable atoms 2s1S0 state. A novel technique atomic allows sensitive measurements fields down about 10 V cm-1. Two-dimensional space time resolved results presented. Sheath voltages, ion net charge densities displacement current directly derived from fields. Under certain assumptions, also electron conduction densities, power dissipated discharge energy distribution function can be inferred. experimental show that common step-model for spatial a reasonable approximation but less appropriate hydrogen. RF-discharge, reversal during anodic phase voltage observed investigated detail. simple analytic model effect developed describes quantitatively results.