Removal of Metallic Deposits by High-Frequency Currents

Abstract

IN examining the spectra of high-frequency discharges in metallic vapours, it was noticed that the wall deposits which had developed under certain conditions disappeared under the electrodes when the field was applied externally. For example, a quartz tube which some years ago had been used to carry an electrodeless discharge, in hydrogen plus iodine, was lying about the laboratory. Its internal wall was covered with a tolerably dense brown coating which moderate heating failed to remove. On applying a high-frequency field by means of external wire electrodes so that a luminous discharge was obtained (in air at a pressure of a few millimetres), in a few minutes the deposit was removed in the neighbourhood of the electrodes. By shifting the position of the electrodes, the whole tube was cleaned in a short time.