Koninklijke Philips Corporation N.V.

Wolfgang Chrost

Rolf Karl Otto Behling

Christoph Helmut Bathe

Michael Lübcke

Gereon Vogtmeier

Rainer Pietig

Astrid Lewalter

The rotatable anode of a rotating anode X-ray source has demanding requirements placed upon it. For example, it may rotate at a frequency as high as 200 Hz. X-ray emission is stimulated by applying a large voltage to the cathode, causing electrons to collide with the focal track. The focal spot generated at the electron impact position may have a peak temperature between 2000&#xb0; C. and 3000&#xb0; C. The constant rotation of the rotating anode protects the focal track to some extent, however the average temperature of the focal track immediately following a CT acquisition protocol may still be around 1500&#xb0; C. Therefore, demanding requirements are placed upon the design of the rotating anode. The present application proposes a multi-layer coating for the target region of a rotating X-ray anode which improves mechanical resilience and thermal resilience, whilst reducing the amount of expensive refractory metals required.

Rotary anode for an X-ray source

The present invention relates to a rotor for an X-ray tube. In order to provide further possibilities for weight reduction in X-ray tubes for providing an increase of rotation frequency, a rotor () for an X-ray tube is provided, comprising a rotational structure () with a plurality of electrically conducting elements (), the ends thereof connected to each other and provided such that an external stator magnetic field generated by a stator induces a current in the electrically conducting elements, which current generates a rotor magnetic field to interact with the stator magnetic field. At least the plurality of electrically conducting elements is made from carbon composite based material.

X-ray tube rotor with carbon composite based material

The invention relates to an X-ray source () with an electron-beam-generator () for generating electron beams (B, B') that converge towards a target (). Thus the spatial distribution of X-ray focal spots (T, T&#x2032;) on the target () can be made denser than the distribution of electron sources (), wherein the latter is usually dictated by hardware limitations. The electron-beam-generator () may particularly comprise a curved emitter device () with a matrix of CNT based electron emitters () and an associated electrode device ().

X-ray source with a plurality of electron emitters

In a rotatable anode () of an X-ray tube, a heat transfer between the rotating disc of the anode () and the second bearing element () is achieved by providing a contact material () within a gap () between the anode disc () and the second bearing element (). Contact elements () protrude from the second bearing element () into the contact material (), thus allowing a heat transfer from anode disc () to second bearing element () via contact material () and contact element ().

Rotatable anode and X-ray tube comprising a liquid heat link

A distributed X-ray source () and an imaging system () comprising such an X-ray source () are proposed. The X-ray source () comprises an electron beam source arrangement () and an anode arrangement (). The electron beam source arrangement () is adapted to emit electron beams () towards at least two locally distinct focal spots () on the anode arrangement (). Therein, the X-ray source is adapted for displacing the anode arrangement () with respect to the electron beam source arrangement (). While the provision of a plurality of focal spots allows acquisition of projection images under different projection angles thereby allowing reconstruction of three-dimensional X-ray images e.g. in tomosynthesis application, a displacement motion of the anode arrangement () with respect to the electron beam source arrangement () may allow for distributed heat flux to the anode arrangement thereby possibly reducing cooling requirements.

Distributed X-ray source and X-ray imaging system comprising the same

X-ray tube and method for determination of focal spot properties The invention relates to an x-ray tube () comprising at least one cathode () which emits electrons accelerated towards a rotating anode () such that the focal spot (7) is formed on a surface () of the anode (). A structure (), in particular slits or pits (), is disposed on the surface () of the anode (). The x-ray tube () comprises a detector () for detecting a detection signal which changes, if the structure () on the rotating anode () passes the focal spot. The x-ray tube () further comprises determination means () for determining properties of the focal spot from changes of the detection signal. Thus, properties of the focal spot can be determined from changes of the detection signal during operation of the x-ray tube ().

X-ray tube and method for determination of focal spot properties

The invention relates to a device for generating X-rays (). The device comprises a source () for generating an electron beam (), and a carrier () which is rotatable about an axis of rotation () and which is provided with a material () which generates the X-rays as a result of the incidence of the electron beam thereon. The device further comprises a heat absorbing member () which is arranged between the source and the carrier to catch electrons, which are scattered back from an impingement position () of the electron beam on the carrier, and to absorb a portion of the radiant heat generated by the carrier when heated during operation. The heat absorbing member is in thermal connection with a cooling system () of the device. According to the invention, the thermal connection between the heat absorbing member () and the cooling system () comprises a thermal barrier () which limits a rate of heat transfer (( ) occurring via the thermal connection per unit of temperature difference between the heat absorbing member and the cooling system. In a particular embodiment, said thermal barrier comprises an annular mounting member () having a limited dimension (hB), by means of which the heat absorbing member is mounted in the device. As a result of said thermal barrier, the heat absorbed by the heat absorbing member is gradually transferred to the cooling system, so that thermal peak loads on the cooling system and problems like boiling of the cooling liquid are avoided. In addition, relatively high temperatures of the heat absorbing member are allowed, so that the mass and volume of the heat absorbing member, which are necessary to provide the heat absorbing member with a sufficiently large heat absorbing capacity, are considerably reduced.

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Hamburg, Germany

Wolfgang Chrost