Studies of Optical Emission and Radical Generation from Atmospheric Pressure Plasma Source Powered by RF in a Hollow Slot Electrode Configuration
Abstract
A hollow slot has been radio frequency electrically excited to generate a discharge plasma at atmospheric pressure. This newly developed micro-plasma device consists of a rf driven hollow electrode, with a long narrow slot of length 3-35 cm, width 0.2 -1.5 mm, and depth 0.7 mm, and a solid transverse electrode which is electrically grounded and placed parallel to the cathode slot with a spacing of 0.1 mm. This two-electrode configuration receives 30 W/cm of rf power with about 150 V of rf voltage applied between the grounded electrode and the rf driven hollow slot electrode. We stabilized the discharge at varying rf frequencies (13.56 MHz, 4 MHz, etc.) in both the hollow cathode and hollow anode modes. Our device design appears scalable to extended length for large surface area processing, utilizing noble gases and their mixtures with oxygen, nitrogen, and hydrogen. A preliminary experiment that ran the torch on argon gas has shown strong line emission in the vacuum UV range. Radical fluxes generated from the RF atmosphere plasma have been measured. The discharge power going to these channels in compared to the input rf power. The latter is determined by careful examination of the rf waveforms and includes harmonic contributions. We have complemented these power measurements by rf circuit models to more clearly identify the hollow cathode and anode modes.
- Publication:
-
APS Division of Atomic, Molecular and Optical Physics Meeting Abstracts
- Pub Date:
- May 2003
- Bibcode:
- 2003APS..DMP.D1077Y