Siemens Aktiengesellschaft

Agfa-gevaert

Agfa Gevaert Nv

Siemens Aktiengesell Schaft

Detlef Mattern

Erich Hell

Peter Schardt

Manfred Fuchs

Sven Fritzler

Joerg Freudenberger

Peter Röhrer

Peter Roehrer

Bernhard Schmitt

Jörg Freudenberger

Hartmut Sklebitz

Markus Schild

Ronald Dittrich

Thomas Ohrndorf

Wolfgang Knüpfer

Stefan Popescu

Paul Leblans

Martin Hoheisel

Eckhard Hempel

Arnulf Oppelt

Peter Hackenschmied

Wolfgang Knuepfer

Wolfgang Kn&uuml;pfer

Matthias Maier

The present embodiments relate to lowering the widening of a radiation beam, for example, using a chamber arranged between a beam output and an object to be irradiated. The chamber is filled with a gas or a gas mixture, the average atomic number of which is smaller than that of air, and the volume expansion of which is changeable. The advantage here is that a widening of a radiation beam caused by multiple scattering is reduced.

Reducing the widening of a radiation beam

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 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

A binderless storage phosphor screen with needle shaped crystals, wherein the phosphor is an alkalihalide phosphor and the needles show high [100] unit cell orientation in the plane of the screen.

Binderless storage phosphor screen with needle shaped crystals

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 device for generation of x-ray radiation has one or more cold electron sources as a cathode and at least one x-ray target as an anode that are arranged in an evacuable housing. Upon application of an electrical voltage between cathode and anode, electrons emitted from the electron source are accelerated in an electron beam onto the x-ray target. A device for reduction of the proportion of positive ions in the region of the electron source is arranged between the electron source and the x-ray target in the housing. The device exhibits a long lifespan with good focusing capability and fast modulation capability of the electron beam.

Device for generation of x-ray radiation with a cold electron source

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 vapor-depositing a substrate with a layer of a needle-shaped x-ray fluorescent material containing at least one alkali metal, alkali halide phases and an alkali halide are mixed in a vapor phase and are vapor-deposited on the substrate. A needle-shaped fluorescent material is thereby produced having the formula wherein Mis at least one metal ion from the group Na, K, Rb and Cs, His at least one halide from the group F, Cl, Br and I and Sis at least one lanthanide ion from the group La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu.

Needle-shaped x-ray fluorescent material and method for vapor-deposition thereof on a substrate

A luminophore plate has a substrate and an auxiliary layer lying thereabove onto which a storage luminophore layer is applied. The auxiliary layer is rastered such that nubs separated by trenches are formed. Luminophore needles of a storage luminophore are formed on the surface of said nubs by vapor deposition.

Luminophore plate

A radiation converter has a radiation absorber for generating photons dependent on the intensity of incident x-ray radiation, a photocathode arranged downstream of the radiation absorber in the radiation propagation direction at a distance therefrom and serving for generating electrons dependent on the photons emerging from the radiation absorber, a device for accelerating the electrons emerging from the photocathode onto an electron detector for generating electrical signals dependent on the impinging electrons, an electron multiplier arranged between the photocathode and the electron detector, the electrons emerging from the photocathode being multiplied by the electron multiplier.

Radiation converter

A method for producing a coating of fluorescent or luminophore material includes the steps of depositing the luminophore material from a vapor phase on a substrate in such a manner that at least 30 weight-% of the luminophore material used is deposited on the substrate and then abrading or polishing the luminophore coating to a predetermined even layer thickness utilizing a polishing agent.

Method for producing a luminophore or fluorescent layer

In a method for improving the optical separation of needle-shaped fluorescent layers, made from a fluorescent material, which are formed by vapor deposition on a substrate, vapor deposition is controlled so that the fluorescent layer is deposited on the substrate with a density which is reduced in comparison to the density that the fluorescent material has as a solid.

Method for improving the optical separation of fluorescent layers

A cooling device for an X-ray source arranged at a gantry rotatable around a rotational axis has a ring-like heat exchanger that is arranged at the gantry and is thermally conductively connected to the X-ray source. The cooling device is useable in a computed tomography apparatus having the X-ray source.

Growing community of inventors

Erlangen, Germany

Detlef Mattern