Microstripline applicators for creating microplasma discharges with microwave energy

A microwave plasma system based on microstripline technology is created and implemented for the experimental investigation of miniature size plasmas. Plasmas are generated across a wide range of input parameters, including pressure variation from below 1 Torr to 1 atm, microwave power at 2.45 GHz from 1 to 30 W, and a variety of discharge sizes and shapes. Data are measured for the discharge power density as a function of discharge pressure, input power and size. The power densities for discharges of diameters in the range 2–0.45 mm vary from 10 to 1000 W cm −3 . Basic characteristics of the plasmas such as the electron temperature, plasma density and gas temperature are measured using probe diagnostics and optical emission spectroscopy (OES). In the range of one to 10 Torr, the electron temperatures are 1.9–2.3 eV, gas temperatures range from 600–1200 K and the plasma densities are in the range of 10 12 –10 15 cm −3 .