By reducing the dimensions of the electrodes to the submillimeter range, it is possible to operate dc gas discharges at pressures up to 760 Torr (argon). A plane geometry for the cathode, different from the well-known microhollow cathode discharge, was used in these experiments. For anode hole diameters smaller than 0.6 mm and pD (D diameter of the anode hole) larger than 9 Torr cm, the differential resistivity in the I–V characteristics is similar to the hollow cathode one. The emission in the visible range is distributed more homogeneously over the entire cathode surface. By using a end-on coupled configuration of hollow and plane cathode geometries, the discharge can be stabilized over the entire (pD) range between 1 and 23 Torr cm. The discharge is stable, for both the hollow–plane and hollow–hollow cathode configurations in aligned geometries.

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