Multi-arrayed micro-patch emitter with integral control grid
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorsGeorge A. Haas, Richard E. Thomas, Richard F. Greene
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Abstract
A multi-arrayed electron emitter for microwave tubes in which the emitting urface is an array of continually replenished low-work-function regions, (micro-patches), whose boundaries include a control grid which is integral with the cathode surface and which controls emission from the low-work-function micro-patches. The continually replenished low-work-function regions are uniformly positioned relative to a matrix of uniformly spaced openings through which the low-work-function material is released.
Claims9
An electron-emitter cathode assembly with an integral control grid which comprises:
- a container for low-work-function material having a porous metal top serving as a cathode, the low-work-function material being dispensed from the pores to the cathode when the container is heated to provide an array of low-work-function electron-emitting areas centered at the pores;
- and
- an insulated grid disposed on the porous metal top of the container and having a plurality of openings, each opening being aligned with a single respective pore to control electron emission from the respective low-work-function electron-emitting area centered at the pore and to contain the spread of low-work-function material,
- the grid being made of a material to which the low-work-function material will not adhere at operating temperatures.
A method of forming an electron-emitter cathode assembly with an integral control grid comprising the steps of:
- forming a container for low-work-function material;
- providing a porous metal top for the container to serve as a cathode, the low-work-function-material being dispensed from the pores to the cathode when the container is heated to provide an array of low-work-function electron-emitters areas centered at the pores;
- disposing on the porous top of the container an insulated grid having a plurality of openings, the grid being made of a material to which the low-work-function material will not adhere at operating temperatures;
- aligning each opening with a single respective pore to control electron emission from the respective low-work-function electron-emitting area centered at the pore and to contain the spread of low-work-function material.
Dependencies are inferred from the claim text.