35results about "X-ray tube gas control" patented technology

A compact, reliable scanning electron-beam x-ray source achieves reduced complexity and cost. In particular, the x-ray source includes an electron beam that is propagated parallel to an x-ray target and is swept across the target in response to a moving magnetic cross field. Rather than scanning the beam by deflecting it about a single point, the point of deflection is translated along the target length, dramatically reducing the volume of the device. The magnetic cross field is translated along the target length using either mechanical systems to move permanent magnets, or electrical systems to energize an array of electromagnets.

A coolant passage is formed inside the rotary shaft while an air passage is formed inside the casing. A mechanical seal is arranged between the coolant passage and the air passage. Leakage cooling water, which has leaked in the form of vapor from the mechanical seal, is relegated radially outwardly along with air by the action of a rotary vane, which is disposed in the air passage, and finally flows out of an air outlet. A coolant sensor may be provided to early detect the leakage water.

Systems, methods, and devices with improved electrode configuration for downhole nuclear radiation generators are provided. For example, one embodiment of a nuclear radiation generator capable of downhole operation may include a charged particle source, a target material, and an acceleration column between the charged particle source and the target material. The acceleration column may include an intermediate electrode that remains floating at a variable potential, being electrically isolated from the rest of the acceleration column.

A compact, reliable scanning electron-beam x-ray source achieves reduced complexity and cost. In particular, the x-ray source includes an electron beam that is propagated parallel to an x-ray target and is swept across the target in response to a moving magnetic cross field. Rather than scanning the beam by deflecting it about a single point, the point of deflection is translated along the target length, dramatically reducing the volume of the device. The magnetic cross field is translated along the target length using either mechanical systems to move permanent magnets, or electrical systems to energize an array of electromagnets.

In accordance with one embodiment, the present technique provides an X-ray source. The X-ray source includes a field emitter array having a plurality of field emitter elements disposed in a vacuum chamber and configured to emit electrons in the vacuum chamber towards an anode assembly. The X-ray source also includes an anode disposed in the vacuum chamber for receiving the electrons emitted by the field emitter array and configured to thereby generate X-ray radiation. The X-ray source further includes a source of cleaning gas coupled to the vacuum chamber, wherein the source of cleaning gas is configured to provide the cleaning gas to the vacuum chamber towards the field emitter array to reduce deposition of contaminants on or to clean contaminates from the field emitter array.

In one embodiment, an X-ray tube includes an electron beam source including a primary cathode configured to emit an electron beam and an anode assembly including an anode configured to receive the electron beam and to emit X-rays when impacted by the electron beam. The X-ray tube also includes an enclosure, at least the primary cathode and the anode being disposed in the enclosure, and a secondary cathode disposed in the enclosure and configured to emit electrons to impact the anode for degassing the enclosure.

Disclosed herein are a high-voltage generator (120) for an x-ray source, an x-ray gun, an electron beam apparatus, a rotary vacuum seal, a target assembly for an x-ray source, a rotary x-ray emission target (500), and an x-ray source. These various aspects may separately and / or together enable the construction of an x-ray source which can operate at energies of up to 500 kV and beyond, which is suitable for use in commercial and research x-ray applications such as computerised tomography. In particular, the high-voltage generator includes a shield electrode (123a, 123b) electrically connected intermediate of a first voltage multiplier (122a, 122b) and a second voltage multiplier (122b, 122c). The electron beam apparatus includes control photodetectors (202a, 202b - not shown) and photo emitters (201a, 202a) having a transparent conductive shield (203a and 203b, 203c - not shown) arranged therebetween. The rotary vacuum seal includes a pumpable chamber (302) at a position intermediate between high-pressure and low- pressure ends of a bore (301) for a rotating shaft (401). The rotary target assembly is configured such that when a torque between a bearing housing (403) and a vacuum housing exceeds a predetermined torque, the bearing housing rotates relative to the vacuum housing. The rotary x-ray emission target (500) has a plurality of target plates (560) supported on a hub, the plates being arranged on the hub to provide an annular target region about an axis rotation of the hub. The x- ray gun is provided with a shield electrode (123a) maintained at a potential difference relative to the x-ray target different to the electron beam emission cathode.

An x-ray tube includes an anode, a first chamber enclosing the anode and having a first pressure therein, a cathode, and a second chamber enclosing the cathode and having a second pressure therein. A separator is positioned between the first and second chambers and has a conductance limiter therein.

A coolant passage is formed inside the rotary shaft while an air passage is formed inside the casing. A mechanical seal is arranged between the coolant passage and the air passage. Leakage cooling water, which has leaked in the form of vapor from the mechanical seal, is relegated radially outwardly along with air by the action of a rotary vane, which is disposed in the air passage, and finally flows out of an air outlet. A coolant sensor may be provided to early detect the leakage water.

X-ray generation tube includes electron gun, and anode having target to generate X-rays upon collision with electrons from the electron gun. The electron gun includes cathode having electron emitting portion, extraction electrode to extract the electrons from the electron emitting portion, and focusing electrode to focus the extracted electrons. The focusing electrode includes first portion having tubular shape, and second portion arranged inside the first portion. The first portion includes distal end facing the anode, the second portion includes opposing surface facing the anode, and the opposing surface includes electron passage hole through which the electrons from the electron emitting portion pass. Distance between the distal end and the anode is shorter than that between the opposing surface and the anode. Thermal conductivity of the distal end is lower than that of the second portion.

A system and method for providing a sealing arrangement in an X-ray tube are provided. The X-ray tube includes a rotating portion having a plurality of ball bearings and a liquid metal within a housing having the ball bearings therein. The rotating portion is configured to rotate an anode. The X-ray tube further includes a sealing portion formed by a liquid metal vacuum interface configured in a radial direction to resist flow of liquid metal from the housing to a vacuum portion.

A system for controlling a gas load imposed upon a high vacuum chamber includes a first chamber enclosing a high vacuum and positioned within an ambient environment, a second chamber enclosing a gas and positioned within the ambient environment adjacent to the first chamber, and a rotatable shaft having a first portion extending into the first chamber and a second portion extending into the second chamber. A ferrofluid seal is positioned about the rotatable shaft and positioned between the first portion and the second portion and the ferrofluid seal fluidically separates the first chamber from the second chamber. A control unit is attached to the second chamber and configured to control the gas enclosed in the second chamber such that a gas load in the first chamber is reduced.

A system and method for providing a sealing arrangement in an X-ray tube are provided. The X-ray tube includes a rotating portion having a plurality of ball bearings and a liquid metal within a housing having the ball bearings therein. The rotating portion is configured to rotate an anode. The X-ray tube further includes a sealing portion formed by a liquid metal vacuum interface configured in a radial direction to resist flow of liquid metal from the housing to a vacuum portion.

An X-ray tube, including: an envelope (11) that holds inside thereof at a predetermined pressure; a filament (12) for emitting electrons and a focus electrode (13) provided in the envelope: and a target (15) for generating X-ray provided in the envelope facing to the filament (12) and the focus electrode (13), wherein the envelope (11) has an envelope body (11a) and an X-ray window portion (16) having a higher X-rays transmissivity and a higher electric conductivity than the envelope body (11a), when the X-ray window portion (16) or the anode (14) is set to a lower electric potential than both of an electric potential of the anode (14) or the X-ray window portion (16) and an electric potential of the filament (12) and the focus electrode (13), detection of at least one of an ion current (Ii) or an electron current (Ie) through the X-ray window portion (16) or the anode (14) is possible.

A rotating anticathode X-ray generating apparatus which is configured such that an X-ray is generated by an irradiation of an electron beam emitted from a cathode includes a rotating anticathode with an electron beam irradiating portion to generate the X-ray through the irradiation of the electron beam so that a direction of the electron beam is set equal to a direction of a centrifugal force caused by a rotation of the rotating anticathode; and a film for covering at least the electron beam irradiating portion so as to prevent an evaporation of a material making the rotating anticathode.

A rotating anticathode X-ray generating apparatus which is configured such that an X-ray is generated by an irradiation of an electron beam emitted from a cathode includes a rotating anticathode with an electron beam irradiating portion to generate the X-ray through the irradiation of the electron beam so that a direction of the electron beam is set equal to a direction of a centrifugal force caused by a rotation of the rotating anticathode; and a film for covering at least the electron beam irradiating portion so as to prevent an evaporation of a material making the rotating anticathode.

An electron beam production and control assembly includes a vacuum chamber, a beam source, and a target. The target has an active section and an inactive section. The active section is adapted to generate x-rays when the beam impinges on the x-ray producing section. The electron beam production and control assembly also includes a focusing unit positioned along the chamber at a location intermediate the rearward end and the forward end. The focusing unit directs the beam towards the target in a converging manner to impinge on the target. The focusing unit sweeps the beam along a scanning path over the active section of the target. The focusing unit moves the beam to a retrace path on the inactive section of the target between sweeps of the scanning path to maintain ion accumulation in the beam between sweeps over the active section.

A bearing structure for an X-ray tube is provided that includes a journal bearing shaft with a radially protruding thrust bearing encased within a bearing sleeve, one of which rotates relative to the other. The stationary component, e.g., the journal bearing and / or the thrust bearing includes at least one vent groove formed therein that improves the ability of the journal bearing structure to enable gases trapped by the liquid metal within the bearing assembly to escape through the vent groove to the exterior of the X-ray tube. By adding a strategically located channel or vent groove of sufficient size in at least one of the journal bearing or the thrust bearing, the pressures resisted by the seal created between the liquid metal and the vent groove(s) in the bearing components is significantly reduced, allowing escape of the gases to avoid detrimental effects to the operation of the X-ray tube, while maintaining the load carrying capacity of the bearing assembly.

Systems, methods, and devices with improved electrode configuration for downhole nuclear radiation generators are provided. For example, one embodiment of a nuclear radiation generator capable of downhole operation may include a charged particle source, a target material, and an acceleration column between the charged particle source and the target material. The acceleration column may include an intermediate electrode that remains floating at a variable potential, being electrically isolated from the rest of the acceleration column.

An x-ray tube includes an anode, a first chamber enclosing the anode and having a first pressure therein, a cathode, and a second chamber enclosing the cathode and having a second pressure therein. A separator is positioned between the first and second chambers and has a conductance limiter therein.

An X-ray tube, including: an envelope (11) that holds inside thereof at a predetermined pressure; a filament (12) for emitting electrons and a focus electrode (13) provided in the envelope: and a target (15) for generating X-ray provided in the envelope facing to the filament (12) and the focus electrode (13), wherein the envelope (11) has an envelope body (11a) and an X-ray window portion (16) having a higher X-rays transmissivity and a higher electric conductivity than the envelope body (11a), when the X-ray window portion (16) or the anode (14) is set to a lower electric potential than both of an electric potential of the anode (14) or the X-ray window portion (16) and an electric potential of the filament (12) and the focus electrode (13), detection of at least one of an ion current (Ii) or an electron current (Ie) through the X-ray window portion (16) or the anode (14) is possible.

A method for generating X-ray radiation is disclosed. The method comprises providing (10) a liquid target (J) in a chamber (120), directing (20) an electron beam (132) towards the liquid target such that the electron beam interacts with the liquid target to generated X-ray radiation (134), estimating (30) a number of particles produced from the interaction between the electron beam and the liquidtarget by measuring a number of positively charged particles in the chamber and eliminating a contribution from scattered electrons to the estimated number of particles, and controlling (40) the electron beam, and / or a temperature in a region of the liquid target in which the electron beam interacts with the target, such that the estimated number of particles is below a predetermined limit. A corresponding X-ray source is also disclosed.

In embodiments, a linac electron beam excited X-ray source weighing less than 50 pounds, and having a volume less than 1 cubic foot, injects electrons from an RF-excited, diamond tip cathode into a dielectric accelerator tube of diameter less than 10 mm, where the electrons are RF-accelerated to 1-4 MeV. A focusing channel having a plurality of annular permanent magnets can surround the dielectric tube, and a vacuum can be maintained in the tube by a getter pump. The accelerating RF can be 10 GHz or higher. The X-ray source can be powered by a rechargeable battery for more than an hour. Embodiments can be transported within a case having a display attached to an interior surface of its lid. An X-ray head can be removed from the case and extended up to 10 feet while remaining interconnected with the case by a flexible conduit.

In embodiments, a linac electron beam excited X-ray source weighing less than 50 pounds, and having a volume less than 1 cubic foot, injects electrons from an RF-excited, diamond tip cathode into a dielectric accelerator tube of diameter less than 10 mm, where the electrons are RF-accelerated to 1-4 MeV. A focusing channel having a plurality of annular permanent magnets can surround the dielectric tube, and a vacuum can be maintained in the tube by a getter pump. The accelerating RF can be 10 GHz or higher. The X-ray source can be powered by a rechargeable battery for more than an hour. Embodiments can be transported within a case having a display attached to an interior surface of its lid. An X-ray head can be removed from the case and extended up to 10 feet while remaining interconnected with the case by a flexible conduit.

A method for generating X-ray radiation is disclosed. The method comprises: providing (10) a liquid target (J) in a chamber (120); directing an electron beam (132) towards the liquid target (20) such that the electron beam interacts with the liquid target to generate x-rays irradiating (134); estimating (30) the number of particles produced by the interaction between the electron beam and the liquid target by measuring the number of positively charged particles in the chamber and eliminating the estimated contribution from scattered electrons the contribution of the number of particles; and controlling (40) the temperature in the region of the electron beam and / or the liquid target in which the electron beam interacts with the target such that the estimated number of particles is below a predetermined limit effect. A corresponding X-ray source is also disclosed.

The object of the present invention is to provide a cold cathode X-ray tube capable of being driven stably over a long period of time by preventing temporal reduction in anode current. A cold cathode X-ray tube 1 comprises an electron emission part 10 including an electron emission element using a cold cathode, an anode part 11 disposed opposite to the electron emission part 10, a target 12 disposed on a part of a surface of the anode part 11, a housing 15 in which the electron emission part 10, the anode part 11, and the target 12 are disposed, and a hydrogen generation part 14 that is made of a material that generates hydrogen when receiving collision of electrons and disposed on a portion other than the surface of the target 12 out of surfaces existing in the housing 15.

Disclosed herein are a high-voltage generator for an x-ray source, an x-ray gun, an electron beam apparatus, a rotary vacuum seal, a target assembly for an x-ray source, a rotary x-ray emission target, and an x-ray source. These various aspects may separately and / or together enable the construction of an x-ray source which can operate at energies of up to 500 kV and beyond, which is suitable for use in commercial and research x-ray applications such as computerised tomography. In particular, the high-voltage generator includes a shield electrode electrically connected intermediate of a first voltage multiplier and a second voltage multiplier. The electron beam apparatus includes control photodetectors and photo emitters having a transparent conductive shield arranged therebetween. The rotary vacuum seal includes a pumpable chamber at a position intermediate between high-pressure and low-pressure ends of a bore for a rotating shaft. The rotary target assembly is configured such that when a torque between a bearing housing and a vacuum housing exceeds a predetermined torque, the bearing housing rotates relative to the vacuum housing. The rotary x-ray emission target has a plurality of target plates supported on a hub, the plates being arranged on the hub to provide an annular target region about an axis rotation of the hub. The x-ray gun is provided with a shield electrode maintained at a potential difference relative to the x-ray target different to the electron beam emission cathode.