GAS DISCHARGE TUBE

摘要

A gas discharge tube for generating discharge between an anode (24) and a cathode (56) disposed in a gas-filled sealed container (12), comprising a tubular discharge path limiting unit (28) having a through hole (42) disposed between the anode and the cathode to constrict a discharge path between the anode and the cathode, and a discharge shielding unit (50) disposed so as to cover the surrounding of the discharge path limiting unit and electrically insulated from the discharge path limiting unit, characterized in that the discharge path limiting unit has its cathode-side end projected a specified amount beyond the surface on the cathode side of the discharge shielding unit, and the end on the anode side projects into a space (62) where the anode is located. This gas discharge tube forms a high-density electron region only in part only of the cathode side of the through hole in the discharge path limiting unit to positively generate a starting discharge, and radiates heat from the anode to reduce evaporated materials from the anode.