公开(公告)号：US3903450A

公开(公告)日：1975-09-02

申请号：US33432573

申请日：1973-02-21

Applicant: HUGHES AIRCRAFT CO

Inventor： FORBESS RONALD A ,  NOLAND JAMES A

IPC: H01J3/02 ,  H01J23/065 ,  H01J29/70

CPC classification number: H01J3/029 ,  H01J23/065

Abstract: A dual-perveance gridded electron gun is disclosed for selectively providing a high-perveance pulsed electron beam and a low-perveance continuous electron beam. A screen grid which projects over a peripheral portion only of an electron emissive cathode surface is disposed between the emissive surface and a control grid which extends substantially across the emissive surface. Relative potentials are applied to the cathode and to the control and screen grids such that in the higher perveance mode substantially all of the cathode emissive surface emits electrons, while in the lower perveance mode electron emission is substantially precluded from the peripheral portion of the emissive surface over which the screen grid projects.

Abstract translation: 公开了一种双重对称网格电子枪，用于选择性地提供高通量脉冲电子束和低通量连续电子束。 仅在电子发射阴极表面的周边部分突出的屏幕网格设置在发射表面和基本上延伸穿过发射表面延伸的控制栅格之间。 相对电位被施加到阴极和控制和屏幕栅格，使得在更高的平均模式中，基本上所有的阴极发射表面发射电子，而在较低的平均模式中，电子发射基本上被排除在发射表面的周边部分 屏幕网格投影。