| 摘要 |
PURPOSE:To prevent a laser device from lessening in output over a long term so as to obtain a stable laser beam by a method wherein a metal electrode is formed of a sintered alloy mainly composed of an alloy of chrome, iron, and nickel and an insulator of alumina, silicon dioxide, or the like. CONSTITUTION:A metal electrode is formed of a sintered alloy mainly composed of alloy particles 21 of chrome, iron, and nickel and alumina particles 22 of insulator. Therefore, electrons -e are uniformly emitted from the alloy particles 21 of chrome, iron, and nickel existing among the alumina particles 22 to enable a glow discharge to start stably. At this point, as the alumina particles 22 are oxide, they are hardly oxidized, so that the surfaces of the alloy particles 21 of chrome, iron, and nickel where electrons are emitted are not screened by oxide, and oxide is never scattered, whereby the inside of a discharge tube is protected against pollution. Moreover, an oxide film 23 of the alloy particle 21 of chrome, iron, and nickel is thin and electrically conductive, so that an electron emitting plane hardly deteriorates and a discharge is stabilized. By this setup, a laser device of this design can be prevented from lessening in output over a long term to output a stable laser beam. |
