Development and characterization of thermoelectron enhanced microplasma devices for the generation of plasmas in micro-sized capillaries

Microplasmas offer the advantage of small size, low power consumption as well as higher rate of materials processing and are therefore promising for new applications in materials processing. While many different types of microplasma devices have been presented in recent years, the effects of the smaller scale on the properties of the plasma (gas and electron temperatures), distribution of electrons, radicals and ions, and the implications of these characteristics for materials processing have not been studied in detail yet. Here we present the generation and characterization by optical emission spectroscopy (OES) as well as the numerical simulation of atmospheric pressure argon microplasmas inside capillaries with inner diameters between 50 micro m and 1 mm using two different types of thennoelectron enhanced microplasma (TEMP) devices. The first type has a freestanding geometry whereas the second type is planar, fabricated by a surface mount technique. The latter allows for future size reduction of the microplasma setup and for an easier integration with other apparatuses and devices.