| 摘要 |
PURPOSE:To reduce an influence by an electric field formed in the tip part on an electric discharge operation, to enhance the stability of the electric discharge operation and to prevent a change in a laser output by a method wherein a firing auxiliary tube is installed and the cross-sectional face in its tip part is worked to be a round and protrusionless shape. CONSTITUTION:A firing auxiliary tube 10a is attached to a tube body of a discharge-tube group 1 situated between an anode 2a and a cathode 3a; and it is connected electrically to the anode 2a. Since the cross-sectional shape in the tip part of the tube 10a is formed to be a round and protrusionless shape, an electric field generated near the tip part does not generate an equipotential line which is swollen toward the inside of a discharge tube. Consequently, it is not required to form an electromagnetic lens inside the discharge tube, and also a streamer is not formed near the tip part of the auxiliary tube 10a when a pulse is oscillated (in a state that the pulse in a pulse-train shape is output on a fixed cycle). Consequently, an electric discharge at a laser oscillator is stabilized, and a stable laser output without change can be obtained. |
