Novel Atmospheric Pressure Inductively Coupled Micro Plasma Source Using Floating Wire Electrode

A novel atmospheric pressure inductively coupled micro-plasma (ICMP) source is proposed. The gas flow channel is prepared inside the center of the U-shaped Cu electrode of a one-turn antenna coil. The plasma region is the center linear trench designed for the optical coupling with the slit aperture of the spectrometer. A floating wire electrode is first placed inside the trench of the gas channel without the wired connection to the power source. A glass window plate covers the gas channel allowing the optical emission from the linear trench. Under He gas flow, the plasma ignites at similar to 18 W of 100 MHz very high frequency (VHF) power, and the optical emission increases with the power. Without the floating wire electrode, the plasma does not ignite even at 200 W. The floating wire electrode enhances the ignition. The characteristics of the floating wire electrode and the ICMP source are described. (C) 2011 The Japan Society of Applied Physics