Micro-hollow-cathode discharge

A number of configurations of microplasma reactors will be described here. Classification will be based on the power sources, the electric field switching frequency ranging from DC to GHz, and electrode geometries and materials, extending from DBDs to micro hollow cathodes and microcavity discharges. 

Probably because the field is relatively young, not much has been reported yet on gas-liquid discharges in a microfluidic (microreactor) format. Yamatake et al. have used a DC-driven atmospheric plasma micro hollow cathode to directly inject O radicals into a fast oxygen gas... 

Preferred methods in trace determination of the elements include atomic absorption spectrometry (AAS), optical emission spectrometry (OES) with any of a wide variety of excitation sources [e.g., sparks, arcs, high-frequency or microwave plasmas (inductively coupled plasma, ICP microwave induced plasma, MIP capacitively coupled micro-wave plasma, CMP), glow discharges (GD). hollow cathodes, or laser vaporization (laser ablation)], as well as mass spectrometry (again in combination with the various excitation sources listed), together with several types of X-ray fluorescence (XRF) analysis [51]. 

---