| 摘要 |
<p>PURPOSE:To obtain an electron beam which high intensity reproductivity by surface finishing a chip made of monocrystal of a hexaboride compound having a calcium hexaboride type structure so that deficiencies such as fine holes or flaws are rarely noticed on its thermal electron emission region. CONSTITUTION:A thermal electron emitting cathode chip made of monocrystal of a hexaboride compound having a calcium hexaboride type crystal structure is constituted so that deficiencies such as fine holes or flaws are rarely noticed on the chip region substantially emitting thermal electrons. Said hexaboride compound having a calcium hexaboride type crystal structure includes LaB6, YB6, GdB6, EnB6, and SmB6, etc. The shape of the thermal cathode chip is subject to no restriction, however in concrete terms, it may be (1) a cone and a pyramid with a spherical tip, and (2) a cone or a pyramid with a flat tip.</p> |
