| 摘要 |
<p>PURPOSE:To maintain characteristic stabilization of emission electrons for a long time in such a way that the tip of the cathode composed of single crystal chips is formed on the surface the minute facets which are emissive of electrons and deposited by evaporation from the crystal surfaces. CONSTITUTION:The structure is made up so that LaB6 single crystal chips 1 which have (100) azimuths as crystal axis are used as the cathode, and its tip includes the plural number of faces (111) so-called ''facets'' formed in asperity. These faces are the same ones which are produced by evaporation from the crystal surfaces by using the cathode, and the convex parts enclosed by four facets 5a-5d are formed into a square pyramidal shape. These facets are precisely formed, and even if they are served for a long time after that, the chip tip form can be always maintained. In consequence, emission electron characteristic can be stabilized.</p> |
