| 摘要 |
<p>A dispenser cathode, in particular a capillary metal cathode, for electrical discharge tubes has a porous emissive material support disc (2) which is made of refractory metal and is situated at the end face, and which has a lateral surface provided with an emission-inhibiting layer (1). In this dispenser cathode, it is intended to improve the focusing of the electron beam by better definition of the position of the cathode and of the Wehnelt cylinder associated with it and by a precisely defined cathode diameter. The invention provides for the emission-inhibiting layer (1) to cover the peripheral zone including the lateral surface of the emissive material support disc (2). The novel dispenser cathode is used as a capillary metal cathode in travelling-wave tubes. <IMAGE></p> |
