| 摘要 |
<p>To stabilize an emission current of a cold cathode electron gun and extend its product life, in a cold cathode electron gun comprising a cold cathode for emitting electrons by field-emission, a gate electrode for controlling the field-emission, a Wehnelt electrode which surrounds the cold cathode and the gate electrode, a first anode for accelerating electrons, and a second anode for constructing an electron lens together with the first anodes the inner diameter of the first anode is greater than a radius of flow of electrons which are emitted in the direction perpendicular to the optical axis of the electron lens. <IMAGE></p> |
