| 摘要 |
<p>The efficiency of a semiconductor cathode can be increased by bombarding the electron-emitting regions (8) with an electron beam (8), which frees the surface from adhered oxygen particles. The electron beam preferably originates from a second semiconductor cathode (42), which has an opening (42) for passing the electron beam (20) of the first semiconductor cathode (20). Alternatively, both semiconductor cathodes can be realized in one semiconductor body.</p> |
