Circuits and methods for electron-beam control
AssigneeHewlett-Packard Development Company, L.P.
InventorRichard Lee Hilton
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Abstract
An electron-beam controller (EBC) capable of controlling the power in an electron-beam is disclosed. The EBC can be implemented with an emitter, an extractor, a current mirror, and an input current having a magnitude responsive to the desired electron beam current. An EBC suited for low-efficiency emitters is also disclosed. A method for controlling the power intensity of an electron-beam over time is also disclosed. The method includes the steps of: (1) providing an emitter at a first voltage, (2) providing a target at a second voltage, (3) introducing an extractor at a controllable third voltage, (4) estimating the actual electron beam energy by sensing the emitter current; and (5) adjusting the third voltage in response to the sensed emitter current.
Claims25
A method for controlling the energy in an electron beam, comprising:
- providing an emitter at a predetermined first voltage, a surface of the emitter defining a first boundary of a gap;
- arranging a target surface disposed from the emitter, the target surface having a predetermined second voltage, the target surface defining a second boundary of the gap, wherein the gap is designated for traversal by the electronic beam;
- introducing an extractor at a controllable third voltage, the extractor at least partially disposed within the gap, wherein the controllable third voltage falls between the first and second voltages and wherein the controllable third voltage induces electrons to exit the emitter by driving an input current having a magnitude equivalent to the current magnitude desired in the electron beam;
- estimating the actual electron beam energy by sensing the emitter current;
- and
- adjusting the third voltage in response to the sensed emitter current.
A method for controlling energy in an electron beam, comprising:
- providing an emitter at a predetermined first voltage, a surface of the emitter defining a first boundary of a gap;
- arranging a target surface disposed from the emitter, the target surface having a predetermined second voltage, the target surface defining an opposing boundary of the gap, wherein the gap is designated for traversal by the electronic beam;
- introducing an extractor at a controllable third voltage, the extractor at least partially disposed within the gap, wherein the controllable third voltage is driven by an input current having a magnitude equivalent to the current magnitude desired in the electron beam and falls between the first and second voltages thereby inducing electrons to exit the emitter;
- estimating the actual electron beam energy by sensing both the emitter current and the extractor current;
- and
- adjusting the third voltage in response to the sensed emitter and extractor currents.
An integrated circuit electron-beam controller, comprising:
- means for setting the voltage at an emitter in response to a predetermined voltage at a target such that a potential difference exists between the emitter and the target;
- means for extracting electrons from the emitter to induce an electron beam to traverse a gap disposed between the emitter and the target;
- means for determining a desired electron beam current magnitude;
- means for indirectly sensing the actual electron beam current;
- means for comparing the indirectly sensed actual electron beam current with the desired electron beam current;
- and
- means for adjusting the extracting means responsive to the comparing means.
An integrated circuit electron-beam energy controller, comprising:
- a target having a predetermined voltage;
- an emitter disposed away from the target, the emitter having a second voltage different from the predetermined voltage at the target such that a voltage difference exists between the emitter and the target;
- an extractor at least partially disposed in a gap bounded by respective surfaces of the target and the emitter, the extractor having a third voltage such that a voltage difference exists between the emitter and the extractor;
- and
- a current mirror electrically coupled to the emitter and the extractor.
Dependencies are inferred from the claim text.