| 摘要 |
PURPOSE:To prevent the deterioration of a discharge gas and the lowering of insulation properties, and to lengthen the lifetime of a laser tube largely by forming a discharge path, in which plasma is brought into contact directly, of boron nitride. CONSTITUTION:An ion laser tube is mainly composed of a laser-tube cathode section 2 housing a coil-shaped cathode 4, a laser-tube anode section 3 housing a cylindrical anode 5, and a laser-tube central section 1 held by the laser-tube cathode section 2 and the anode section 3. The laser-tube central section 1 has structure in which discoid members 7 made of aluminum nitride and cylindrical connecting members 8 are connected alternately in a coaxial manner in the axial direction of a laser tube. Openings demarcated by the internal sidewalls of cylindrical members 9 made of BN(boron nitride) fitted into the central openings 10 of the discoid members 7 form discharge paths 12 on the axis of the laser tube. A plurality of openings 11 shape gas feedback paths 13 for equalizing gas pressure between the cathode section 2 and the anode section 3. Accordingly, insulation deterioration between a cathode and an anode is prevented, thus lengthening the lifetime of the laser tube. |
