| 摘要 |
PURPOSE:To obtain a multilayer cathode with little alteration of electric current properties of a heat generating material and low electric power consumption by composing the heat generating material of a multilayer cathode with a material of mainly zirconium boride or titanium boride. CONSTITUTION:A heat generating body 12 and an electron radiation material layer 6 are formed on an insulating substrate 1 and the heat generating body 12 of a multilayer cathode is composed with zirconium boride ZrB2 or titanium boride TiB2. Since the heat generating body 12 prepared from zirconium boride or titanium boride is stable at high temperature against an insulating substrate 1 of tungsten, wear of the heat generating body 12 during operation is low. As a result, a multilayer cathode with little alteration of properties for a long duration can be obtained. |
