摘要 |
An electrode includes thorium as a minor component for a high-pressure discharge lamp, where the electrode rod is free of thorium/thorium oxide, or comprises thorium/thorium oxide, as a minor constituent. A covering member made of refractory metal, free of thorium/thorium oxide, is circumference coated on the electrode rod in the vicinity of the discharge side tip. The entire surface of the electrode rod is completely coated over the range where the covering member extends. The electrode rod tip of the electrode rod is not, or at least partly, coated with the covering member. The part of the electrode tip, which is not coated by the covering member, is free of thorium/thorium oxide.
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