Devices having an electron emitting structure

An x-ray emitting device comprising:

• an x-ray emitting construct, an electron emitting construct, at least one spacer, a voltage source and a gate interconnect lead;
• said at least one spacer situated such that the x-ray emitting construct and the electron emitting construct face each other;
• an evacuated inner gap between said x-ray emitting construct and said electron emitting construct;
• said x-ray emitting construct comprising an anode, the anode being an x-ray target;
• and
• said electron emitting construct comprising at least one active zone, each of said at least one active zone comprising a plurality of active areas, each said active area comprising:
• (a) a cathode;
• (b) a gated cone electron source, comprising a plurality of emitter tips arranged in an array;
• (c) a resistive layer situated between the gated cone electron source and the cathode;
• and
• (d) a gate electrode comprising a plurality of gate holes, the position of at least one of said plurality of gate holes corresponding to the position of at least one of said plurality of emitter tips;
• wherein each of said plurality of emitter tips is configured to emit an electron beam towards the x-ray emitting construct;
• wherein the gate electrode is connected to said voltage source through said gate interconnect lead;
• and
• wherein one or more subsets of said plurality of active areas are capable of being activated independently such that total emission current of the electron emitting construct is tunable by controlled activation of one or more of said active zones.

A method for controlling total emission current of an electron emitting construct in an x-ray emitting device comprising:

• providing a cathode;
• providing a plurality of active areas each active area having a gated cone electron source, comprising a plurality of emitter tips arranged in an array;
• a gate electrode;
• and a gate interconnect lead connected to said gate electrode;
• providing an x-ray emitting construct comprising an anode, the anode being an x-ray target;
• situating said x-ray emitting construct facing said active areas face each other;
• selecting a set of active areas;
• and
• activating selected active areas by conductively connecting a voltage source to their associated said gate electrode interconnect lead.