Discharge tube apparatus

摘要

Discharge tube apparatus includes an outer containing vessel and a structure comprising for example five metal cylinders located co-axially within it. Each of the metal cylinders includes projecting spacers on its outer surface which serve to space it from adjacent ones. Such a structure is thermally insulating and may be arranged to enable a large temperature difference to be maintained between the interior of the discharge tube and the outer containing vessel. In other embodiments, a plurality of structures are included disposed along the axis of the tube. Also, dispenser segments for dispensing part of the active medium of a metal vapor laser may be included and arranged to shield vulnerable surfaces in the tube from direct exposure to the discharge.