| 摘要 |
PURPOSE:To provide a thin arc tube having a mechanical strength and an anticorrosion property to bear a high linear transmissivity to a visible light, and a poor operating ambiance exposing to a metallic gas of a radical reacting property at a high temperature and a high pressure. CONSTITUTION:The mean particle diameter of crystal particles is 1mum or less and the maximum particle diameter is 2mum or less and the crystal particles has a very minute cystal structure compared with conventional translucent alumina. Furthermore, it forms almost no intercrystalline phase such as a spinel phase. As a result, since the crystal particle diameter is made minute and a poor intercrystalline phase is not formed, the mechanical strength is improved from the normal temperature to the discharge temperature, and an arc tube 1A can be made in a thin thickness. And the influences of the intercrystalline phase and the crystalline interface in the crystal particles which have functioned as a cause of scattering the light are eliminated, and the linear transmissivity to the visible light is improved. |
