| 摘要 |
PURPOSE:To reduce the sputtering of a directly heated impregnation type cathode so as to lengthen a gas laser tube in life by a method wherein the cathode is formed into a two layered structure that Sc2O3 is contained only in the surface of the cathode. CONSTITUTION:In a gas laser tube with a spiral directly heated impregnation type cathode 12 arranged about an optical axis, the surface of the base formed of high melting point metal of the cathode 12 is made to contain Sc2O3 so as to make the cathode have a two layered structure. When the surface of the cathode 12 is impregnated with Sc2O3, the operating temperature of the cathode 12 can be effectively reduced, and the sputtering from the cathode can be decreased in result. By this setup, a gas laser tube can be made long in life. |
