Large-area individually addressable multi-beam x-ray system and method of forming same
First Claim
1. A structure to generate x-rays comprising:
- a stationary cathode structure having a plurality of stationary and individually electrically addressable field emissive electron sources defining a plurality of cathodes, each cathode disposed on a first side of the cathode structure;
a stationary target structure having a deflection surface oriented non-perpendicularly to the first side of the cathode structure, the deflection surface defining a target;
an object positioner disposed within an imaging zone; and
a detector operatively positioned within the structure to receive and detect an x-ray from the target, wherein each cathode comprises a substrate and a gate electrode positioned parallel to and insulated from the substrate, the substrate comprising a field emissive material.
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Accused Products
Abstract
A structure to generate x-rays has a plurality of stationary and individually electrically addressable field emissive electron sources with a substrate composed of a field emissive material, such as carbon nanotubes. Electrically switching the field emissive electron sources at a predetermined frequency field emits electrons in a programmable sequence toward an incidence point on a target. The generated x-rays correspond in frequency and in position to that of the field emissive electron source. The large-area target and array or matrix of emitters can image objects from different positions and/or angles without moving the object or the structure and can produce a three dimensional image. The x-ray system is suitable for a variety of applications including industrial inspection/quality control, analytical instrumentation, security systems such as airport security inspection systems, and medical imaging, such as computed tomography.
197 Citations
59 Claims
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1. A structure to generate x-rays comprising:
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a stationary cathode structure having a plurality of stationary and individually electrically addressable field emissive electron sources defining a plurality of cathodes, each cathode disposed on a first side of the cathode structure;
a stationary target structure having a deflection surface oriented non-perpendicularly to the first side of the cathode structure, the deflection surface defining a target;
an object positioner disposed within an imaging zone; and
a detector operatively positioned within the structure to receive and detect an x-ray from the target, wherein each cathode comprises a substrate and a gate electrode positioned parallel to and insulated from the substrate, the substrate comprising a field emissive material. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of generating an x-ray image comprising the steps of:
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positioning an object within an imaging zone;
switching each of a plurality of cathodes on a stationary cathode structure at a predetermined frequency to field emit an electron, each of the plurality of cathodes individually addressable and electrically switched in a programmable sequence to field emit electrons toward an incidence point on a stationary target structure, the cathode comprising a field emissive electron source;
emitting an x-ray from a target of the stationary target structure at the predetermined frequency;
imaging the object; and
detecting the emitted x-ray, wherein a position on the stationary target structure from which the x-ray emits corresponds spatially and temporally to a position on the cathode structure from which the electron emits, and wherein at least one of a circumferential position and an elevation angle of the emitted x-ray is sufficiently discriminated with respect to the object to produce a three dimensional image. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 37, 38, 39, 40, 41)
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24. A structure to generate x-rays comprising:
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a plurality of stationary and individually electrically addressable electron sources defining a plurality of cathodes;
at least one target placed opposing the cathodes; and
an evacuated chamber that houses the plurality of cathodes and the at least one target.
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36. A device to record x-ray images, comprising:
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an x-ray source comprising a plurality of stationary and individually electrically addressable electron sources defining a plurality of cathodes, the plurality of cathodes disposed on a face of a first planar surface, at least one target disposed on a second planar surface, a deflection surface of the second planar surface opposing the face of the first planar surface, and an evacuated chamber that houses the plurality of cathodes and the at least one target;
an array or matrix of x-ray detectors or x-ray sensitive films opposing the x-ray source, the array or matrix substantially parallel to and at equal distance to the x-ray source; and
an object positioner placed between the x-ray source and the array or matrix.
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42. A method to obtain an x-ray image, the method comprising:
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placing an object in an x-ray source, the x-ray source comprising a plurality of stationary and individually electrically addressable electron sources defining a plurality of cathodes, the plurality of cathodes disposed on a face of a first planar surface, at least one target disposed on a second planar surface, a deflection surface of the second planar surface opposing the face of the first planar surface, and an evacuated chamber that houses the plurality of cathodes and the at least one target, an array or matrix of x-ray detectors or x-ray sensitive films opposing the x-ray source, the array or matrix substantially parallel to and at equal distance to the x-ray source, and an object positioner placed between the x-ray source and the array or matrix;
applying power to at least one of the plurality of cathodes to generate x-ray radiation for a pre-set exposure time;
exposing the object to the x-ray radiation; and
capturing an x-ray image corresponding to the object by either the x-ray detectors or the x-ray sensitive films. - View Dependent Claims (43, 44, 45, 46, 47, 49, 50, 51, 52, 53)
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48. A device to record x-ray images comprising:
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an x-ray source comprising a plurality of stationary and individually electrically addressable electron sources defining a plurality of cathodes, the plurality of cathodes disposed on a surface of a first ring, at least one target disposed on a second ring, a deflection surface of the second ring opposing the surface of the first ring, and an evacuated chamber that houses the plurality of cathodes and the at least one target;
an array or matrix of x-ray detectors or x-ray sensitive films on a surface opposing the x-ray source, the array or matrix substantially concentric to and at equal distance to the x-ray source; and
an object positioner placed between the x-ray source and the array or matrix.
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54. A method to obtain an x-ray image, the method comprising:
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placing an object in an x-ray source, the x-ray source comprising a plurality of stationary and individually electrically addressable electron sources defining a plurality of cathodes, the plurality of cathodes disposed on a surface of a first ring, at least one target disposed on a second ring, a deflection surface of the second ring opposing the surface of the first ring, and an evacuated chamber that houses the plurality of cathodes and the at least one target, an array or matrix of x-ray detectors or x-ray sensitive films on a surface opposing the x-ray source, the array or matrix substantially concentric to and at equal distance to the x-ray source, and an object positioner placed between the x-ray source and the array or matrix;
applying power to all of the plurality of cathodes to generate x-ray radiation for a pre-set exposure time;
exposing the object to the x-ray radiation; and
capturing an x-ray image corresponding to the object by either the x-ray detectors or the x-ray sensitive films. - View Dependent Claims (55, 56, 57, 58, 59)
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Specification