| 摘要 |
<p>PURPOSE:To increase the luminous output and obtain a stable and long life by mixing high-melting point metal powder, scandium oxide powder and/or yttrium oxide powder, molding the mixture into a cathode shape with a sharp tip, then sintering it. CONSTITUTION:A cathode with a sharp tip is formed, a cathode forming material is composed of high-melting metal and scandium oxide and/or yttrium oxide, the powder of them is mixed and molded, it is then sintered into the cathode for a discharge tube. A combined material or an alloy made of some of tungsten, molybdenum, ruthenium, indium, and osmium is used for the high- melting point metal powder. Scandium oxide powder 5-30wt.% and yttrium oxide powder 0-5wt.% are used, for example. High-melting point metal powder and an electron emitting material are mixed and press-molded, it is then sintered in vacuum or the reducing atmosphere to obtain a cathode with the porosity of 15-40%.</p> |
