| 摘要 |
<p>A high power switching apparatus (100) comprises an annular cathode having a surface capable of emitting a hollow electron beam therefrom and an anode cavity spaced from said cathode. The cavity has an annular opening (151) smaller in dimension than a corresponding internal dimension that defines the cavity to provide a Faraday cage collector (150) of the hollow electron beam. A control electrode (38, 39), disposed between the cathode and the anode cavity in a non-intercepting position relative to the hollow electron beam, provides a controlling electric field region for modulation of the hollow electron beam. Arc suppressing electrodes (33, 34), at approximately the same potential as the cathode, are disposed between the control electrode and the anode. An intermediate high voltage electrode (184, 186), disposed between the arc suppressing electrodes and the anode cavity in a non-intercepting position relative to the hollow electron beam, provides a controlling electric field region for channeling of the hollow electron beam. The intermediate high voltage electrode maintains a positive voltage with respect to the cathode in order to provide an intermediate voltage step between the cathode and the anode in the off state and to channel the hollow electron beam towards the anode in the on state. A voltage, positive with respect to the cathode, is applied to the control electrode in order to draw the hollow electron beam from the emitting surface of the cathode and into the anode. The potential of the anode is generally positive with respect to the cathode, however, it needs not be at a potential as high as that of the control electrode, especially when electrons are being drawn from the cathode.</p> |
