| 摘要 |
1,114,048. Electrode materials and processing. TESLA NARODNI PODNIK. 7 Dec., 1965 [16 Dec., 1964], No. 51816/65. Heading H1D. Thoriated electrodes of a rare gas discharge lamp operating with an inside wall temperature of 500-1000‹ C. and a temperature of at least part of the electrode surface not less than 1700‹ C., are produced by including in the tube filling at least 0. 1 mg. of powdered thorium and at least 0.001 micromole per cc. of discharge space of halogen or halogen compound of one or several metals of the first, second, third or fourth group, or the group of rare earths of the periodic system; evacuating the discharge tube; filling the tube with a rare gas ; and thereafter sealing the tube and ageing. During initial operation of the lamp, the thorium is converted to the thorium halide, transported as a vapour to the electrode, the halide decomposed and the thorium metal deposited on the electrode. The powdered thorium may be introduced as a suspension in an organic solvent, or incorporated in the electrode structure or placed on an electrode surface before sealing the tube. The quartz tube may also contain sodium, mercury, thallium, indium, scandium or gallium at at least 0.001 micromole per c.c. of discharge space. The halide may be the bromide or iodide. The halide further provides a continuous clean-up process for the tube envelope, removing sputtered thorium and redepositing it on the cathode. |
