Abstract: An x-ray imaging system has an x-ray source having an electron field emission source that emits an x-ray beam that strikes an elongated, stationary anode in an evacuated housing. A magnetic deflection system steers the electron beam between the electron field emission source and the anode, so that the electron beam can strike the anode at different locations, thereby causing x-rays to be emitted from those different locations, by controlling the degree of magnetic deflection. A radiation detector detects the x-rays after attenuation by an examination subject, and generates signals dependent on the detected radiation that represent an image of the subject.

Abstract: A method for producing radioactive isotopes for positron emission tomography is provided. The method includes generating radioactive isotopes by the acceleration of a projectile in a linear accelerator that is operative to accelerate at least two different projectiles.

Abstract: A cathode has an emission layer that thermionically emits electrons upon exposure with a laser beam. The material of the emission layer has a product of density (?), measured in kg m 3 , heat capacity (Cp), measured in J kg ? ? K and heat conductivity (?), measured in W mK that is, at room temperature, maximally 500,000 J 2 m 4 ? K 2 ? s . Such a cathode has an improved thermionic emission of electrons.

Abstract: An electron source has an electron emitter, an anode, a voltage source connected between the electron emitter and the anode, as well as a switch connected with the electron emitter. The switch is fashioned as a optoelectronic switching element.

Abstract: An x-ray radiator has an anode that emits x-rays, a cathode that thermionically emits electrons upon irradiation thereof by a laser beam, a voltage source for application of a high voltage between the anode and the cathode for acceleration of the emitted electrons toward the anode to form an electron beam, a vacuum housing, an insulator that is part of the vacuum housing and that separates the cathode from the anode, an arrangement for cooling components of the x-ray radiator, a deflection and arrangement that deflects the laser beam from a stationary source, that is arranged outside of the vacuum housing, to a spatially stationary laser focal spot on the cathode.

Abstract: An electron source has an electron emitter, an anode, a voltage source connected between the electron emitter and the anode, as well as a switch connected with the electron emitter. The switch is fashioned as a optoelectronic switching element.

Abstract: An x-ray apparatus that has at least one radiator module (1) with a vacuum housing. The at least one radiator module is arranged at least partially around an examination space. The apparatus has an anode segment and, opposite the anode segment, at least two potential-separated cathode segments are arranged in the vacuum housing. The cathode segments thermionically emit electrons upon exposure with laser light. The electrons strike the anode segment and generate x-ray radiation of corresponding energy. Such an x-ray apparatus is more simple structured in terms of design.

Abstract: An x-ray unit has an x-ray radiator having an anode that emits x-rays upon being struck by electrons, a cathode that thermionically emits electrons upon irradiation thereof by a laser beam, electrical connections for application of a high voltage between the anode and the cathode to accelerate the emitted electrons toward the anode as an electron beam, a vacuum housing that can be rotated around an axis, an insulator that is part of the vacuum housing and that separates the cathode from the anode, a drive that rotates the vacuum housing around its axis, an arrangement for cooling components of the x-ray radiator, and an arrangement that directs the laser beam from a stationary source, arranged outside of the vacuum housing, onto a spatially stationary laser focal spot on the cathode and that focuses the laser beam.

Abstract: A cathode has an emission layer that thermionically emits electrons upon exposure with a laser beam. The material of the emission layer has a product of density (?), measured in kg m 3 , heat capacity (Cp), measured in J kg ? ? K and heat conductivity (?), measured in W mK that is, at room temperature, maximally 500,000 J 2 m 4 ? K 2 ? s . Such a cathode has an improved thermionic emission of electrons.

Abstract: The invention concerns an x-ray detector with a plurality of layers arranged one top of one another in the incident direction of the x-rays, whereby each of the layers comprises at least one photodiode and a luminophore layer applied thereon.

Abstract: An x-ray apparatus has at least one radiator module with a sealed vacuum housing and a high voltage connection. The at least one radiator module extends only partially around an examination space and has at least two x-ray sources that can be controlled individually.

Abstract: An x-ray radiator has a vacuum housing that can rotate around an axis, a cathode that thermionically emits electrons upon irradiation thereof by a laser beam, an anode that emits x-rays upon being struck by the electrons, an insulator that is part of the vacuum housing and that separates the cathode from the anode, electrodes or terminals to apply a high voltage between the anode and the cathode to accelerate the emitted electrons toward the anode to form an electron beam, a drive arrangement for rotation of the vacuum housing around its axis, an arrangement for cooling components of the x-ray radiator, and an arrangement that directs and focuses the laser beam from a stationary source that is arranged outside of the vacuum housing onto a spatially stationary laser focal spot on the cathode.

Abstract: A rotating envelope radiator has a radiator housing surrounded by an external housing to form an intervening space in which a coolant flows. To prevent the formation, at high rotational frequencies, of reverse flows of the coolant in the intervening space, a flow conductor structure is provided in the intervening space that counteracts the formation of tangential flow components in the coolant.

Abstract: In a method for operating an x-ray device, an x-ray beam is generated at a focal spot of a rotary anode that is rotatable around a rotation axis, and the x-ray beam is gated with a slit-shaped diaphragm to produce a fan-shaped x-ray beam, that is moved through an examination region in the manner of a scan. To improve the image resolution, the fan-shaped x-ray beam can be moved over the examination region essentially in the direction of the rotational axis of the rotary anode by tilting the x-ray tube on the focal spot, with the x-ray tube being tilted on the focal spot so that the fan-shaped x-ray beam is always gated from the region of the overall emitted x-ray beam having the highest image resolution or the highest image definition in the movement through the examination region.

Abstract: A method for producing radioactive isotopes for positron emission tomography is provided. The method includes generating radioactive isotopes by the acceleration of a projectile in a linear accelerator that is operative to accelerate at least two different projectiles.

Abstract: An x-ray radiator has an anode that emits x-rays when struck by electrons, a cathode that thermionically emits electrons upon irradiation thereof by a laser beam, a voltage source for application of a high voltage between the anode and the cathode for acceleration of the emitted electrons towards the anode to form an electron beam. A surface of the cathode that can be irradiated by the laser beam is at least partially roughened and/or doped and/or is formed of an intermetallic compound or vitreous carbon.

Abstract: An x-ray radiator has an anode that emits x-rays, a cathode that thermionically emits electrons upon irradiation thereof by a laser beam, a voltage source for application of a high voltage between the anode and the cathode for acceleration of the emitted electrons toward the anode to form an electron beam, a vacuum housing, an insulator that is part of the vacuum housing and that separates the cathode from the anode, an arrangement for cooling components of the x-ray radiator, a deflection and arrangement that deflects the laser beam from a stationary source, that is arranged outside of the vacuum housing, to a spatially stationary laser focal spot on the cathode.

Abstract: An x-ray unit has an x-ray radiator having an anode that emits x-rays upon being struck by electrons, a cathode that thermionically emits electrons upon irradiation thereof by a laser beam, electrical connections for application of a high voltage between the anode and the cathode to accelerate the emitted electrons toward the anode as an electron beam, a vacuum housing that can be rotated around an axis, an insulator that is part of the vacuum housing and that separates the cathode from the anode, a drive that rotates the vacuum housing around its axis, an arrangement for cooling components of the x-ray radiator, and an arrangement that directs the laser beam from a stationary source, arranged outside of the vacuum housing, onto a spatially stationary laser focal spot on the cathode and that focuses the laser beam.

Abstract: In a method for estimating the remaining life span of an X-ray radiator that has been installed in an X-ray apparatus and is operational, under specified test conditions and at time intervals, a measurement value that is indicative for the remaining life span of the X-ray radiator is determined and stored in a memory. A forecasted progression of future measurement values is then forecasted from the instantaneous measurement value and previous measurement values that were determined under identical test conditions, which also are stored in the memory. The forecasted remaining life span of the X-ray radiator is then determined based on the forecasted progression and a limit value that is associated with the individual X-ray radiator, which is stored in the memory.

Abstract: A thermionic flat electron emitter has an emitter arrangement with an emitter plate having slits therein that produce serpentine current paths. The emitter arrangement has a structure that, in operation, causes the electron density of the emitted electrons to be lower in the central region of the emitter plate than in a region adjoining the central region.