| 摘要 |
PURPOSE:To prevent a cathode from shifting for obtaining a gas laser tube with higher reliability, by a method wherein the length of the cylindrical cathode installed in a cylindrical glass vessel so as to contact with its inner surface is made equal to the intrnal length of the glass tube practically. CONSTITUTION:A gas laser tube 1 constitutes a vacuum vessel from a cylindrical glass vessel 2, outer enclosing parts 5, 6 and a pair of mirrors 7, 8, and gas such as He, Ne, etc., is filled into the inside of said vessel. Inside the tube, a cylindrical cathode 9 and an anode 11 are arranged, and electric discharge is performed between the cathode and the anode. The cylindrical cathode 9 is practically equal to the internal diameter of said cylindrical glass vessel 2 in its outer diameter, and it does not move in the radial direction. As for the movement in the axial direction of the cathode, it is suppressed by equalizing the length of the cathode 9 with the internal length of the glass vessel 2 approximately. With the situation, a laser tube having good operating and life characteristics is obtained. |
