| 摘要 |
PURPOSE:To enhance efficiency of laser beam oscillation, by a structure wherein at least one of electrodes for discharge is formed by an electrode pipe with a bore of the substantial same size as that of a capillary section, so as to be concentric with the capillary section. CONSTITUTION:In a discharge tube 12, the bore of the middle section along longitudinal direction is made small to form a capillary section 13. An electrode pipe 18 constituting a hollow electrode is in contact with one end of the capillary section 13. This electrode pipe 18 is formed by a thin wall stainless pipe with a bore size (d) of about 2.4-8mm. In this connection, the bore size (d) is preferably either the same as that of the capillary section 13 or somewhat larger than that thereof. And, edge section on the side of an anode 15 of the electrode pipe 18 is covered with a fitting edge 19 so as not to be exposed in the discharge tube 12. Thus, the edge section is prevented from being exposed, and thereby generation of discharge is prevented from being biased at the edge section, so that the discharge is uniformly generated throughout the inner peripheral surface of the electrode pipe 18. |
