Micro-structured electrode arrays: glow discharges in Ar at atmospheric pressure using a variable radio frequency generator

Micro-structured electrode (MSE) arrays consist of an interlocked, comb like, capacitive electrode system with gap widths in the µm-range. The usage of the Paschen similarity law (pd = const.) enabled us to generate large area uniform glow discharges up to atmospheric pressure with our arrays. In order to ignite glow discharges at atmospheric pressure this approach is established next to using dielectric barrier arrays and plasma jets. Because of the industrial, scientific and medical (ISM) limitation of available radio frequencies the usual frequency for experiments is 13.56 MHz. With a variable radio frequency generator, it is possible to extend the applicability of the MSE arrays in order to gain more information about the frequency dependent breakdown mechanisms and to confirm the underlying theory. The electric parameters of the non-thermal plasma system are characterized by a special probe with an upper frequency detection limit of 60 MHz