High-pressure scanning tunnelling microscopy study of microscopic gas discharges

A high-pressure scanning tunnelling microscope was built to study the behaviour and properties of microscopic electrical gas discharges. Gas discharges could be produced with different electrode geometries and materials in a wide pressure range of 1-200 bar. The influence of these parameters on the formation of a plasma, occurring at the breakdown of an electrical gas discharge, is discussed in detail. The properties of a plasma in a high-pressure environment are compared to those in low-pressure regimes, An experimental set-up was designed for detailed plasma diagnostics by means of optical spectroscopy. First measurements of spectra show that this approach is suitable for the investigation of microscopic gas discharges. Copyright (C) 1999 John Wiley & Sons, Ltd.