The rf Micro-Hollow Device

The rf Micro-Hollow Device (rfMHD) is a new micro-plasma source with which we aim to provide sub 10 micron plasmas and densities $>$10$^{22 }$m$^{-3}$. Applications include targeted processing for electronic {\&} bio-materials, gas sensors and light sources. The micron-scale dimensions and near atmospheric pressure operation give new physics at turn on and during steady state operation. RfMHDs of 25 microns diameter have been demonstrated[1]; they ignite readily and operate stably at powers less than 10W. The rfMHD device will be introduced and its operation described. Results from electrical and optical measurements {\&} their analysis will be presented. Potential processes contributing to ignition {\&} sustainment will be discussed. The prospects of operating with smaller source diameters {\&} the science required to describe operation at these reduced scales will be addressed. The rfMHD will be presented in the context of biomedical applications currently of interest to this centre.\\[4pt] [1] Mahony, Gans, Graham, Maguire {\&} Petrovic, 2008 \textit{Appl Phys Lett} \textbf{93} 011501