X-ray detector with picosecond time resolution
AssigneeKMS Fusion, Inc.
InventorStephen B. Segall
Life of this patent
Estimating the term…
Abstract
An X-ray detector for obtaining time resolved signals from intense pulsed X-ray sources, such as from a fuel pellet during a laser fusion process. The detector has a cathode which emits electrons when bombarded by X-rays from the fuel pellet. The electrons are accelerated by an electron accelerator to relativistic velocities and impinge on a Cherenkov emitter which radiates light. An optical system collects and focuses the radiated light onto an image converter streak camera or other fast photodetector to provide a trace of the light intensity as a function of time. Time resolved images of the fuel pellet may be produced by the detector and recorded by an image converter streak camera or by a camera using an optical Kerr cell shutter.
Claims42
An x-ray detector comprising, a plurality of cathodes each adapted to emit electrons when irradiated by x-rays, an electron accelerator for accelerating electrons emitted by each of said cathodes to a relativistic velocity, a Cherenkov emitter associated with each of said cathodes and receiving electrons from its associated cathode after the electrons have been accelerated by said electron accelerator and emitting light, and an optical system associated with each of said Cherenkov emitters for collecting and focusing at least part of the light from its associated Cherenkov emitter on a photodetector, and a photodetector for detecting at least part of the light collected by said optical systems from said Cherenkov emitters.
An x-ray detector comprising, a cathode adapted to emit electrons when irradiated by x-rays, an electron accelerator for accelerating electrons emitted by said cathode to a relativistic velocity, a Cherenkov emitter receiving accelerated electrons from said electron accelerator and emitting light, an optical system for collecting at least part of the light from said Cherenkov emitter, a photodetector for detecting at least part of the light collected by said optical system from said Cherenkov emitter, and said electron accelerator comprises a pair of parallel plates of an electrically conductive material with one of said plates having said cathode thereon and the other of said plates engaging the entrance face of said Cherenkov emitter through which accelerated electrons enter into said Cherenkov emitter.
An x-ray detector comprising, a cathode adapted to emit electrons when irradiated by x-rays, an electron accelerator for accelerating electrons emitted by said cathode to a relativistic velocity, a Cherenkov emitter receiving accelerated electrons from said electron accelerator and emitting light, an optical system for collecting at least part of the light from said Cherenkov emitter, a photodetector for detecting at least part of the light collected by said optical system from said Cherenkov emitter, imaging means forming an image of the source of x-rays, and means producing a magnetic field parallel to the desired direction of axial acceleration of electrons by said electron accelerator, said electron accelerator and said cathode being within said magnetic field such that said magnetic field decreases the magnitude of the transverse excursion of electrons emitted from said cathode, whereby the image resolution of the detector is improved.
An x-ray detector comprising, a cathode adapted to emit electrons when irradiated by x-rays, an electron accelerator for accelerating electrons emitted by said cathode to a relativistic velocity, a Cherenkov emitter receiving accelerated electrons from said electron accelerator and emitting light, an optical system for collecting at least part of the light from said Cherenkov emitter, a photodetector for detecting at least part of the light collected by said optical system from said Cherenkov emitter, and said Cherenkov emitter comprises an emitter lens having a plane entrance face through which accelerated electrons pass which is perpendicular to the axis of the lens and a conical exit surface from which light emitted by the accelerated electrons passes, said conical exit surface having a half angle chosen so that light rays within a given range of wavelengths which are emitted in a plane defined by the axis of the lens and any radius vector of the lens perpendicular to the axis thereof will be refracted by the conical surface into rays of light substantially parallel to the optical axis of said emitter lens.
An x-ray detector comprising, a cathode adapted to emit electrons when irradiated by x-rays, an electron accelerator for accelerating electrons emitted by said cathode to a relativistic velocity, a Cherenkov emitter receiving accelerated electrons from said electron accelerator and emitting light, an optical system for collecting at least part of the light from said Cherenkov emitter, a photodetector for detecting at least part of the light collected by said optical system from said Cherenkov emitter, and said Cherenkov emitter comprises an emitter prism having a plane entrance face through which accelerated electrons pass which is perpendicular to the axis of said emitter prism and a conical reflecting surface from which light emitted by the accelerated electrons is reflected, said conical reflecting surface having a half angle chosen so that light rays which are emitted in a plane defined by the axis of said emitter prism and any radius vector of said emitter prism perpendicular to the axis thereof will be reflected by said conical reflecting surface into rays of light substantially parallel to the optical axis of said emitter prism.
An x-ray detector comprising, a cathode adapted to emit electrons when irradiated by x-rays, an electron accelerator for accelerating electrons emitted by said cathode to a relativistic velocity, a Cherenkov emitter receiving accelerated electrons from said electron accelerator and emitting light, an optical system for collecting at least part of the light from said Cherenkov emitter, a photodetector for detecting at least part of the light collected by said optical system from said Cherenkov emitter, and said Cherenkov emitter comprises a thin slab emitter and the relativistic velocity of electrons accelerated by said electron accelerator and impinging on the entrance face of said thin slab emitter is both greater than one over the index of refraction of said thin slab emitter and less than the square root of the quantity of one over the square of the index of refraction of said thin slab emitter minus one.
An x-ray detector comprising, a cathode adapted to emit electrons when irradiated by x-rays, an electron accelerator for accelerating electrons emitted by said cathode to a relativistic velocity, a Cherenkov emitter receiving accelerated electrons from said electron accelerator and emitting light, a spherical optical system for collecting at least part of the light from said Cherenkov emitter, a photodetector for detecting at least part of the light collected by said optical system from said Cherenkov emitter, said Cherenkov emitter comprises a fiber optic plate having a plurality of transparent fibers each embedded in an opaque cladding having a lower index of refraction than that of said fibers, each said fiber being constructed and arranged with an entrance face and an exit face essentially perpendicular to the longitudinal axis of said fiber and said longitudinal axis extending essentially parallel to the path of accelerated electrons entering said fiber through said entrance face, and the electrons accelerated by said electron accelerator and entering said transparent fibers of said fiber optic plate having a relativistic velocity which is less than one over the index of refraction of said opaque cladding, less than the square root of the quantity of one over the square of the index of refraction of said transparent fibers minus one, and also greater than one over the index of refraction of said transparent fibers.
An x-ray detector comprising, a cathode adapted to emit electrons when irradiated by x-rays, imaging means forming on said cathode an image of the source of x-rays, an electron accelerator for accelerating electrons emitted by said cathode to a relativistic velocity, a Cherenkov emitter receiving accelerated electrons from said electron accelerator and emitting light, an optical system for collecting at least part of the light from said Cherenkov emitter, a photodetector for detecting at least part of the light collected by said optical system from said Cherenkov emitter, means producing a magnetic field parallel to the desired direction of axial acceleration of electrons by said electron accelerator, said electron accelerator and said cathode being within said magnetic field such that said magnetic field decreases the magnitude of the transverse excursion of electrons emitted from said cathode such that the image resolution of the detector is improved, said Cherenkov emitter comprises a fiber optic plate having a plurality of transparent fibers embedded in an opaque cladding having a lower index of refraction than that of said fibers, and the electrons accelerated by said electron accelerator and entering said transparent fibers of said fiber optic plate having a relativistic velocity which is less than one over the index of refraction of said opaque cladding, less than the square root of the quantity of one over the square of the index of refraction of said transparent fibers minus one, and also greater than one over the index of refraction of said transparent fibers.
An x-ray detector comprising a cathode adapted to emit electrons when irradiated by x-rays, an electron accelerator for accelerating electrons emitted by said cathode to a relativistic velocity, a Cherenkov emitter receiving accelerated electrons from said electron accelerator and emitting light, imaging means forming an image on said cathode of the source of such x-rays, and means producing a magnetic field parallel to the desired direction of axial acceleration of electrons by said electron accelerator, said electron accelerator and said cathode being within said magnetic field such that said magnetic field decreases the magnitude of the transverse excursion of electrons emitted from said cathode whereby the image resolution of the detector is improved.
A detector of a flux of high energy charged particles comprising a Cherenkov emitter receiving at least a portion of the charged particles and emitting light, an optical system for collecting at least a portion of the light from said Cherenkov emitter, a photodetector having a time resolution of less than 100 picoseconds for detecting and recording at least part of the light collected by said optical system, said Cherenkov emitter comprising an emitter lens having a plane entrance face through which charged particles pass which is essentially perpendicular to the axis of said emitter lens and a conical exit surface from which light emitted by said charged particles passes, said conical exit surface having a half angle chosen so that light rays within a given range of wave lengths which are emitted in a plane defined by the axis of said emitter lens and any radius vector of said emitter lens perpendicular to the axis thereof will be refracted by the conical surface into rays of light substantially parallel to the optical axis of said emitter lens.
A detector of a flux of high energy charged particles with relativistic velocities comprising a Cherenkov emitter receiving at least a portion of the charged particles and emitting light, an optical system for collecting at least a portion of the light from said Cherenkov emitter, a photodetector having a time resolution of less than 100 picoseconds for detecting and recording at least part of the light collected by said optical system, and said Cherenkov emitter comprising an emitter prism having a plane entrance face which is perpendicular to the axis of said emitter prism and through which at least a portion of the charged particles pass and a conical reflecting surface from which light emitted by the charged particles is reflected, said conical reflecting surface having a half angle chosen so that light rays which are emitted in a plane defined by the axis of said emitter prism and any radius vector of said emitter prism perpendicular to the axis thereof will be reflected by said conical reflecting surface into rays of light substantially parallel to the optical axis of said emitter prism.
A detector of a flux of high energy charged particles with relativistic velocities comprising a Cherenkov emitter receiving at least a portion of the charged particles and emitting light, an optical system for collecting at least a portion of the light from said Cherenkov emitter, a photodetector having a time resolution of less than 100 picoseconds for detecting and recording at least part of the light collected by said optical system, said Cherenkov emitter comprises a thin slab emitter and the relativistic velocity of the charged particles impinging on the entrance face of said thin slab emitter is both greater than one over the index of refraction of said thin slab emitter and less than the square root of the quantity of one over the square of the index of refraction of said thin slab emitter minus one.
A detector of a flux of high energy charged particles with relativistic velocities comprising a Cherenkov emitter receiving at least a portion of the charged particles and emitting light, an optical system for collecting at least a portion of the light from said Cherenkov emitter, a photodetector having a time resolution of less than 100 picoseconds for detecting and recording at least part of the light collected by said optical system, and said Cherenkov emitter comprises a fiber optic having a plurality of transparent fibers embedded in an opaque cladding having a lower index of refraction than that of said fibers, each said fiber being constructed and arranged with an entrance face and an exit face essentially perpendicular to the longitudinal axis of said fiber and said longitudinal axis extending essentially parallel to the path of charged particles entering said fiber through said entrance face, and said charged particles upon entering said fibers of said optic plate having a relativistic velocity which is less than one over the index of refraction of said opaque cladding, less than the square root of the quantity of one over the square of the index of refraction of said transparent fibers minus one, and also greater than one over the index of refraction of said transparent fibers.
A detector of a flux of high energy charged particles with relativistic velocities comprising a Cherenkov emitter receiving at least a portion of the charged particles and emitting light, an optical system for collecting at least a portion of the light from said Cherenkov emitter, a photodetector having a time resolution of less than 100 picoseconds for detecting and recording at least part of the light collected by said optical system, said Cherenkov emitter comprises a fiber optic plate having a plurality of transparent fibers each embedded in an opaque cladding having a lower index of refraction than that of said fibers, each said fiber being constructed and arranged with an entrance face and an exit face essentially perpendicular to the longitudinal axis of said fiber and said longitudinal axis extending essentially parallel to the path of the charged particles entering said fiber through said entrance face, and the charged particles entering said transparent fibers of said fiber optic plate having a relativistic velocity which is less than one over the index of refraction of said opaque cladding, less than the square root of the quantity of one over the square of the index of refraction of said transparent fibers minus one, and also greater than one over the index of refraction of said transparent fibers.
Dependencies are inferred from the claim text.