| 摘要 |
PURPOSE:To restrain oxidation from progressing on the surface of an electrode and to stabilize discharge by a method wherein an inlet for the introduction of an inert gas is provided in the vicinity of a discharge sustaining electrode. CONSTITUTION:In the vicinity of a cathode electrode 2 to emit electrons, an inlet 7 is provided for the supply of an inert gas or a gas containing much inert gas. Said gas to be supplied through the inlet 7 shields the surface of the cathode electrode 2 against a laser gas containing oxygen and, at the same time, cool the electrode surface. Further, a layer containing much inert gas formed on the electrode surface results in a lowered oxygen potential on the electrode surface for restraining oxidation from progressing on the electrode surface. |
