Siemens Aktiengesellschaft

Siemens Aktiengesell Schaft

Peter Schardt

Erich Hell

Detlef Mattern

Jörg Freudenberger

Manfred Fuchs

Sven Fritzler

Thomas Ohrndorf

Joerg Freudenberger

Josef Deuringer

Markus Schild

Ronald Dittrich

Peter Röhrer

Peter Roehrer

Eberhard Lenz

Wolfgang Knuepfer

Stefan Setzer

Frank Sprenger

Guenter Schwierz

Jutta Rother, Legal Representative

Jens Uecker

Detleff Mattern

Wolfgang Kn&uuml;pfer

Matthias Maier

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.

Method for producing radioactive isotopes for positron emission tomography

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 (&#x3c1;), measured in heat capacity (C), measured in and heat conductivity (&#x3bb;), measured in that is, at room temperature, maximally 500,000 Such a cathode has an improved thermionic emission of electrons.

Laser stimulated cathode

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.

Electron source

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.

X-ray radiator with a photocathode irradiated with a deflected laser beam

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. The x-ray unit furthermore has a control circuit with which an operating property of the x-ray unit is adjusted and at least one measurement element for measurement of a measurement quantity is effectively correlated with the temperature of the cathode. The control circuit adjusts the operating property dependent on the measurement of the measurement quantity.

X-ray unit having an x-ray radiator with a thermionic photocathode and a control circuit therefor

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.

X-ray detector and method for production of x-ray images with spectral resolution

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.

X-ray radiator with thermionic emission of electrons from a laser-irradiated cathode

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.

Rotating envelope x-ray radiator

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.

X-ray device that emits an x-ray beam with a scanning-like movement

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.

Method for estimating the remaining life span of an X-ray radiator

An x-ray device includes an x-ray tube for generation of an x-ray emanating from a focal spot of a rotary anode rotatable around a rotation axis and a slit-shaped diaphragm for generation of a fan-shaped x-ray beam that is gated from the x-ray and emission 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.

An x-ray radiator with an anode accommodated in a housing such that it can rotate around an axis has a device for determination of the position of an x-ray-emitting focal spot on the anode. To increase the measurement precision, the device includes a collimator aligned on the focal spot.

X-ray radiator with collimated focal spot position detector

A high-performance anode plate for a directly cooled rotary piston x-ray tube is formed of a high-temperature-resistant material such as tungsten, molybdenum or a combination of both materials. In the region of the focal spot path, the underside of the anode plate is shaped, and/or in this region a different highly heat-conductive material is inserted or applied, such that an improved heat dissipation and thus a lower temperature gradient results.

High-performance anode plate for a directly cooled rotary piston x-ray tube

A monochromator to be used in an X-ray device having an X-ray source is formed by a crystal for spectral restriction of X-rays produced by the X-ray source. The monochromator includes a positioning device that can move the crystal so that it changes the spectral composition of the X-radiation. The crystal can be moved so that it changes the angle between an X-ray path and the crystal, or so that the crystal is removed out of X-ray path or returned into it.

Monochromator for an X-ray radiator allowing modification of the X-ray spectral composition

A rotary piston tube for an x-ray radiator is provided in which the vacuum housing, accommodating an anode and a cathode and displaceable in rotation, comprises a 360&#xb0; all-around ray exit window. For optimization of the ray exit window, this is produced according to one of the subsequently stated material specifications: a) a high-temperature steel or a high-temperature chromium and/or nickel alloy, listed in the standard EN 10273 and EN 10302, at a wall thickness between 0.1 to 0.4 mm; b) a titanium material at a wall thickness between 0.2 and 2 mm; and c) a ceramic material at a wall thickness between 1 mm and 5 mm.

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Höchstadt A.D. Aisch, Germany

Peter Schardt