Improvements in discharge tubes.

摘要

Conventional discharge tubes comprise electrodes within a separate containing vessel. The electrodes are joined to an external circuit by electrical conductors which pass through the vessel wall via an insulated side arm. Such a construction has disadvantages in that careful manufacture is required and it is also difficult to produce a desired distribution of the active medium in a laser and maintain a stable optimim temperature. In an attempt to reduce these problems the discharge vessel 1 comprises electrical conductors 2 and insulators 3 arranged alternately so that a separate discharge vessel is not required. Since the discharge vessel 1 is partially thermally conducting temperature control is facilitated by its fast response to stabilizing controls, heat being supplied from an external source 7. When metal is used as all or part of the active medium the electrodes 2 are lined on their inner surfaces with the metal and each of the electrodes 2 can be controlled independently from the others to obtain a desired distribution of metal vapour.