Abstract: Maximum capillary discharge (bore) length within the distance available between the end mirrors in a gas laser assembly to thereby obtain maximum active gain length for the laser, is accomplished by utilizing a closed ended aluminum cathode in the glass envelope assembly. The cathode is arranged to shield a nickel-iron alloy end plate for the envelope and is attached directly to this end plate to effect both electrical contact by way of the end plate and at the same time be properly mechanically supported. The shape of the closed end of the cathode is further designed to provide for a more uniform current density distribution when the laser is operating. Further, small openings may be provided to admit ions into the area adjacent to the discharge capillary tube thereby facilitating initial breakdown of the gases in the laser when starting the laser.