| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a cold negative electrode electron gun which form 5 an electron beam with a small ripple as well as a high current density by converging electrons emitted from its cold negative electrode. SOLUTION: This apparatus comprises a negative electrode substrate 5 in with at least one of its surfaces is electrically conductive; and an emitter 10 which is formed on the substrate 5 and sharpened in its tip; and an insulation layer 6 laminated on the substrate 5 except the emitter 10 and its vicinity; and a ringed gate electrode 7 laminated in the insulation layer 6 with an opening surrounding the emitter 10; and an inner electrode 8 laminated on the insulation layer 6 and formed at the inside of the gate of electrode 7; and an outer electrode 9 laminated on the insulation layer 6 and formed at the outside of the gate electrode 7. On the condition that each applied voltage to the gate electrode 7, the inner electrode 8 and the outer electrode 9 are respectively termed EG, EI, and Eo in the basis of the electric potential of the emitter 10 EG>=EI, and besides EG>=EO are obtained.</p> |
