Ulrich Kogelschatz: an appreciation

Abstract

Ulrich Kogelschatz has been awarded the A. H. von Engel prize for his `Important contributions to the principles and applications of dielectric barrier discharges'.Ulrich Kogelschatz was born in 1937 in Germany. He obtained his academic education from 1957 to 1967 at Kiel University, one of the early centres of plasma physics in Germany. After finishing his doctoral thesis he worked at the NASA Langley Research Center at Hampton, Virginia, USA, and later joined the Brown Boveri Corporate Research Center at Baden, Switzerland.Originally U. Kogelschatz investigated the generation of ozone in so-called `silent discharges'. To begin with, he clarified experimentally the fundamental properties of the individual filaments. In a subsequent step he and his collaborators supplemented the experiments by a detailed numerical modelling of the reaction kinetics in these pulsed high-pressure glow discharges. They used the insight gained from these investigations to improve existing technical ozonizers enormously. Nobody had expected that basic research on a discharge more than 100 years old could have such far-reaching technical and economic consequences.With this detailed knowledge of the properties of this discharge Kogelschatz realized that this type of highly anisothermic plasma could be used for the generation of incoherent excimer radiation. Once again he made several important contributions, both in terms of fundamental research and in transferring this knowledge to technical applications.The outcome was the development of high-power excimer lamps. It should also be noted that the development of plasma displays which use Xe2-excimer radiation from microscopic dielectric barrier discharges benefited from his research.The success of the dielectric barrier discharge, and the simplicity of its realization, stimulated a large amount of research into the potential of this transient high-pressure glow discharge for use in plasma chemistry. This is another outcome of the work done by Kogelschatz. Moreover, he also contributed personally to the development of this field. Such research may be important in the future for the cleaning of the exhaust gases of combustion engines, and for the production of hydrogen from hydrocarbons.In addition to his research work on dielectric barrier discharges, he has made important contributions to the plasma physics of high-voltage circuit breakers and corona discharges, and to their application in electrostatic precipitators for power plants.Ulrich Kogelschatz has undertaken scientific work on dielectric barrier discharges as a senior scientist at the ASEA-Brown Boveri Research Centre in Baden, Switzerland. He has shown with his outstanding scientific work that basic research can be combined with investigation of applications, leading to economically important technical devices. This is a difficult task, especially in an industrial laboratory, and it is a shining example for research workers in academic institutions.