Abstract:
The present invention generally relates to systems and methods for generating controllable beam of electrons using a hollow-cathode triode electron gun that substantially mitigate impact of back-streaming electrons.
Abstract:
The invention relates to a cathode arrangement (20) comprising: • - a thermionic cathode comprising an emission portion (30) provided with an emission surface for emitting electrons, and a reservoir (38) for holding a material, wherein the material, when heated, releases work function lowering particles that diffuse towards the emission portion and emanate at the emission surface at a first evaporation rate; • - a focusing electrode (40) comprising a focusing surface for focusing the electrons emitted from the emission surface of the cathode; and • - an adjustable heat source (50) configured for keeping the focusing surface at a temperature at which accumulation of work function lowering particles on the focusing surface is prevented.
Abstract:
A cathode assembly is for use in a radiation generator and includes an ohmically heated cathode, and a support having formed therein a hole and a recess at least partially surrounding the hole. In addition, there is a mount coupled to the support. The mount includes a larger outer frame positioned within the recess, a smaller inner frame carrying the ohmically heated cathode and spaced apart from the larger outer frame, and a plurality of members coupling the smaller inner frame to the larger outer frame.
Abstract:
One embodiment disclosed relates to an electron source for generating an electron beam. The electron source includes an electron emitter having a tip from which an electron beam is extracted. The electron further includes a non-planar extractor with an extractor opening and a built-in beam-limiting aperture. The extractor opening is larger than the beam-limiting aperture, and central axes of both the extractor opening and the beam-limiting aperture are aligned with the tip along a beam axis. Another embodiment relates to a method of generating an electron beam using an electron source having a non-planar extractor. Another embodiment relates to an array of electron sources for generating an array of electron beams. The array of electron sources includes an array of electron emitters and an array of non-planar extractor structures. Other embodiments, aspects and features are also disclosed.
Abstract:
The disclosure relates to an image capture device comprising an electron receiving construct and an electron emitting construct, and further comprising an inner gap providing an unobstructed space between the electron emitting construct and the electron receiving construct. The disclosure further relates to an x-ray emitting device comprising an x-ray emitting construct and an electron emitting construct, said x-ray emitting construct comprising an anode, the anode being an x-ray target, wherein the x-ray emitting device may comprise an inner gap providing an unobstructed space between the electron emitting construct and the x-ray emitting construct. The disclosure further relates to an x-ray imaging system comprising an image capture device and an x-ray emitting device.
Abstract:
An electron beam sterilizing device, comprises: an electron- generating filament; a beam-shaper; an output window; a high-voltage supply, capable of creating a high-voltage potential between the electron-generating filament and the output window, for acceleration of electrons; a high-voltage supply for driving current through the electron-generating filament; a control unit for controlling the operation of the electron beam sterilizing device. The device is characterized in that the electron beam sterilizing device has at least three operational states: - an OFF-state, where there is no drive current through the electron-generating filament, - an ON-state, where the electron-generating filament is kept at a temperature above the emission temperature so as to generate electrons for sterilization, and - a standby state, between the OFF-state and ON-state, where the electron- generating filament is kept at a predetermined temperature just below the emission temperature, wherein the control unit is able to control the device to assume the standby state.
Abstract:
An electron gun (1) includes an emitter (2), a tubular support (3) and an adaptor (4) for receiving the emitter. The adaptor includes a tapered plugging surface (7) and the tubular support includes a correspondingly tapered seating surface (9) for receiving the plugging surface. The plugging surface and seating surface have conical profiles which help to position the adaptor concentrically with the support.
Abstract:
A high power switching apparatus (100) comprises an annular cathode having a surface capable of emitting a hollow electron beam therefrom and an anode cavity spaced from said cathode. The cavity has an annular opening (151) smaller in dimension than a corresponding internal dimension that defines the cavity to provide a Faraday cage collector (150) of the hollow electron beam. A control electrode (38, 39), disposed between the cathode and the anode cavity in a non-intercepting position relative to the hollow electron beam, provides a controlling electric field region for modulation of the hollow electron beam. Arc suppressing electrodes (33, 34), at approximately the same potential as the cathode, are disposed between the control electrode and the anode. An intermediate high voltage electrode (184, 186), disposed between the arc suppressing electrodes and the anode cavity in a non-intercepting position relative to the hollow electron beam, provides a controlling electric field region for channeling of the hollow electron beam. The intermediate high voltage electrode maintains a positive voltage with respect to the cathode in order to provide an intermediate voltage step between the cathode and the anode in the off state and to channel the hollow electron beam towards the anode in the on state. A voltage, positive with respect to the cathode, is applied to the control electrode in order to draw the hollow electron beam from the emitting surface of the cathode and into the anode. The potential of the anode is generally positive with respect to the cathode, however, it needs not be at a potential as high as that of the control electrode, especially when electrons are being drawn from the cathode.
Abstract:
An electron accelerator (10) includes a vacuum chamber (46) having an electron beam exit window (24). An electron generator (31) is positioned within the vacuum chamber for generating electrons. A housing (30) surrounds the electron generator and has a first series of openings (34) formed in the housing between the electron generator and the exit window for allowing electrons to accelerate from the electron generator out the exit window in an electron beam when a voltage potential is applied between the housing and the exit window. The housing also has a second series and third series of openings (35) formed in the housing on opposite sides of the electron generator for causing electrons to be uniformly distributed across the electron beam by flattening electrical field lines between the electron generator and the exit window.