Study of micro-glow discharges as ion sources for ion mobility spectrometry

We develop a microionizer as the ion source in a miniaturized spectrometerlike gas analyzer, operating at atmospheric pressure. Several options for the ionizing principle were considered. The application of dc glow discharge in a microsystem was studied in detail and first devices were fabricated and tested. We obtained stable dc plasmas in micromachined electrode gaps from 1 to 50 μm width, at pressures up to 105 Pa in various gases. With 1 and 3 μm gaps, stable glow was achieved at atmospheric pressure in Ar and N2, respectively. In a macrosystem, we extracted ions from a dc glow discharge and controlled the ion flow with a grid.