| 摘要 |
<p>An impregnated cathode structure using an impregnated cathode substrate which includes a large grain size, low porosity region and a small grain size, high porosity region disposed on the side of an electron emission surface of the large grain size, low porosity region, having a mean grain size smaller than a mean grain size in the large grain size, low porosity region and having a porosity greater than the porosity in the large grain size, low porosity region, and which is impregnated with an electron emission material.</p> |
