Abstract: A cathode for an X-ray tube, an X-ray tube, a system for X-ray imaging, and a method for an assembly of a cathode for an X-ray tube include a filament, a support structure, a body structure, and a filament frame structure. The filament is provided to emit electrons towards an anode in an electron emitting direction, and the filament at least partially includes a helical structure. Further, the filament is held by the support structure which is fixedly connected to the body structure. The filament frame structure is provided for electron-optical focusing of the emitted electrons, and the filament frame structure is provided adjacent to the outer boundaries of the filament. The filament frame structure includes frame surface portions arranged transverse to the emitting direction, and the filament frame structure is held by the support structure.

Abstract: The present invention relates to a cathode for an X-ray tube, an X-ray tube, a system for X-ray imaging, and a method for an assembly of a cathode for an X-ray tube. In order to provide a cathode with an improved and facilitated assembly, a cathode (10) for an X-ray tube is provided, comprising a filament (12), a support structure (14), a body structure (16), and a filament frame structure (18). The filament is provided to emit electrons towards an anode in an electron emitting direction (24), and the filament at least partially comprises a helical structure (26). Further, the filament is held by the support structure, which is fixedly connected to the body structure. The filament frame structure is provided for electron-optical focussing of the emitted electrons, and the filament frame structure is provided adjacent to the outer boundaries of the filament.

Abstract: An embodiment of the invention relates to a cathode cup (20) comprising a receptacle for holding an electron emitter (21), wherein the cathode cup is provided at least in the area facing the electron emitter (21) with a surface comprising a plurality of cavities (23). Further, the invention provides an electron source and an x-ray system comprising such a cathode cup (20).

Abstract: An X-ray tube (1) comprising a cathode (3), an anode (5) and a further electrode (7) is proposed. Therein, the further electrode is arranged and adapted such that, due to impact of 'free electrons (27) coming from the anode (5), the further electrode (7) negatively charges to an electrical potential lying between a cathode's potential and an anode's potential. The further electrode (7) may be passive, i.e. substantially electrically isolated and not connected to an active external voltage supply. The further electrode (7) may act as an ion pump removing ions from within a primary electron beam (21) and furthermore also removing atoms of residual gas within the housing (11) of the X-ray tube (1). In order to further increase the ion pumping capability of the further electrode (7), a magnetic field generator (61) can be arranged adjacent to the further electrode (7).

Abstract: A thermionic electron emitter (1) is proposed comprising an inner part (2) including a heatable flat emission surface (3) and an outer part (4) including a surrounding surface (6) substantially enclosing the emission surface and a heating arrangement for heating the emission surface to a temperature for thermionic electron emission. The outer part is mechanically connected to the inner part in a connection region (10) apart from the emission surface. Furthermore, the surrounding surface is thermally isolated, e.g. by a gap (14), from the emission surface in an isolation region apart from the connection region. By providing a surrounding surface enclosing the emission surface which may be on a similar electrical potential as the emission surface but which can have a substantially lower temperature than the emission surface without influencing the temperature distribution within the emission surface, an improved electron emission distribution and homogeneity can be obtained.

Abstract: Scattered electron collector comprising a heat absorbing member having a first end, a second end, an outer periphery and a central bore (14, 16), wherein the central bore is formed in longitudinal direction through the heat absorbing member from the first end to the second end, and a cooling element (50) having an outer periphery and an inner periphery (52). The outer periphery (12) of the heat absorbing member is adapted to be in contact with the inner periphery of the cooling element. Further, at least one slot (20) is formed from the central bore in the direction to the outer periphery of the heat absorbing member to reduce compression stress within the heat absorbing member.

Abstract: A thermionic electron emitter (1) is proposed comprising an emitter part (2) with a substantially flat electron emission surface (3) and a bordering surface (5) adjacent thereto. In order to better absorb main stress loads (L) induced by external forces, the emitter part is provided with an anisotropic polycrystalline material having a crystal grain structure of elongated interlocked grains the longitudinal direction (G) of which is oriented substantially perpendicular to the direction (L) of the main stress loads occurring under normal operating conditions.

Abstract: The invention relates to an X-ray tube with a cathode, generating an electron beam, and an ion-deflecting and collecting setup (IDC), consisting of a single pair of electrodes, wherein the first electrode has a positive supply and the second electrode has either an actively or a passively generated negative voltage, compared to ground potential. Further, the invention relates to a method of voltage supplying of a deflecting and collecting setup (IDC) consisting of a single pair of electrode, wherein the first electrode has a positive voltage potential and the second electrode has either an actively or a passively generated negative voltage, compared to ground potential.

Abstract: An embodiment of the invention relates to a cathode cup (20) comprising a receptacle for holding an electron emitter (21), wherein the cathode cup is provided at least in the area facing the electron emitter (21) with a surface comprising a plurality of cavities (23). Further, the invention provides an electron source and an x-ray system comprising such a cathode cup (20).

Abstract: It is described an emitter (26, 40) for X-ray tubes comprising: a flat foil with an emitting section (30, 46); and at least two electrically conductive fixing sections (31-34; 41-44); wherein the emitting section (30, 46) is unstructured.

Abstract: The present invention relates to a device (20) and a method for sensorless measuring a mechanical rotor frequency of a rotor (6) of an asynchronous machine (40), wherein the rotor (6) has a predetermined defect and the asynchronous machine (40) has a fixed number of pairs of poles. The asynchronous machine (40) comprises a current determination unit (2) for determining a stator current of the stator (7), wherein the stator current has a stator frequency. A processing unit (3) forms a stator current spectrum of the stator current. An analyzing unit (4) analyzes the stator current spectrum and determines an inverse peak (26) and a corresponding inverse frequency in the stator current spectrum, wherein the inverse peak (26) is the peak having the second highest amplitude in the stator current spectrum in the frequency range of the stator frequency.

Abstract: An X-ray tube (1) comprising a cathode (3), an anode (5) and a further electrode (7) is proposed. Therein, the further electrode is arranged and adapted such that, due to impact of ‘free electrons (27) coming from the anode (5), the further electrode (7) negatively charges to an electrical potential lying between a cathode's potential and an anode's potential. The further electrode (7) may be passive, i.e. substantially electrically isolated and not connected to an active external voltage supply. The further electrode (7) may act as an ion pump removing ions from within a primary electron beam (21) and furthermore also removing atoms of residual gas within the housing (11) of the X-ray tube (1). In order to further increase the ion pumping capability of the further electrode (7), a magnetic field generator (61) can be arranged adjacent to the further electrode (7).

Abstract: It is described an emitter (26, 40) for X-ray tubes comprising: a flat foil with an emitting section (30, 46); and at least two electrically conductive fixing sections (31-34; 41-44); wherein the emitting section (30, 46) is unstructured.

Abstract: It is described an electron optical arrangement, a X-ray emitting device and a method of creating an electron beam. An electron optical apparatus (1) comprises the following components along an optical axis (25): a cathode with an emitter (3) having a substantially planar surface (9) for emitting electrons; an anode (11) for accelerating the emitted electrons in a direction essentially along the optical axis (25); a first magnetic quadrupole lens (19) for deflecting the accelerated electrons and having a first yoke (41); a second magnetic quadrupole lens (21) for further deflecting the accelerated electrons and having a second yoke (51); and a magnetic dipole lens (23) for further deflecting the accelerated electrons.

Abstract: According to an exemplary embodiment an x-ray tube comprises a cathode, rotable disc anode, and a focal spot modulating unit, wherein the cathode is adapted to emit an electron beam, and wherein the focal spot modulating unit is adapted to modulate the electron beam in such a way that an intensity distribution of the electron beam on a focal spot on the anode is asymmetric such that the intensity of the electron beam on the focal spot is higher at the front of the focal spot with respect to the rotation direction.

Abstract: Scattered electron collector comprising a heat absorbing member having a first end, a second end, an outer periphery and a central bore (14, 16), wherein the central bore is formed in longitudinal direction through the heat absorbing member from the first end to the second end, and a cooling element (50) having an outer periphery and an inner periphery (52). The outer periphery (12) of the heat absorbing member is adapted to be in contact with the inner periphery of the cooling element. Further, at least one slot (20) is formed from the central bore in the direction to the outer periphery of the heat absorbing member to reduce compression stress within the heat absorbing member.

Abstract: A thermionic electron emitter (1) is proposed comprising an emitter part (2) with a substantially flat electron emission surface (3) and a bordering surface (5) adjacent thereto. In order to better absorb main stress loads (L) induced by external forces, the emitter part is provided with an anisotropic polycrystalline material having a crystal grain structure of elongated interlocked grains the longitudinal direction (G) of which is oriented substantially perpendicular to the direction (L) of the main stress loads occurring under normal operating conditions.

Abstract: A thermionic electron emitter (1) is proposed comprising an inner part (2) including a heatable flat emission surface (3) and an outer part (4) including a surrounding surface (6) substantially enclosing the emission surface and a heating arrangement for heating the emission surface to a temperature for thermionic electron emission. The outer part is mechanically connected to the inner part in a connection region (10) apart from the emission surface. Furthermore, the surrounding surface is thermally isolated, e.g. by a gap (14), from the emission surface in an isolation region apart from the connection region. By providing a surrounding surface enclosing the emission surface which may be on a similar electrical potential as the emission surface but which can have a substantially lower temperature than the emission surface without influencing the temperature distribution within the emission surface, an improved electron emission distribution and homogeneity can be obtained.

Abstract: The invention relates to an X-ray tube with a cathode, generating an electron beam, and an ion-deflecting and collecting setup (IDC), consisting of a single pair of electrodes, wherein the first electrode has a positive supply and the second electrode has either an actively or a passively generated negative voltage, compared to ground potential. Further, the invention relates to a method of voltage supplying of a deflecting and collecting setup (IDC) consisting of a single pair of electrode, wherein the first electrode has a positive voltage potential and the second electrode has either an actively or a passively generated negative voltage, compared to ground potential.

Abstract: The invention describes an emitter device (10) and a method for precisely mounting a thin film electron emitter foil into a cathode cup. Therefore, small fixing bars (71) are realized to keep fine and hence weak emitter structures in position while fixing this setup onto a cathode cup. After mounting those temporary structures are removed (72) to get the final functional emitter-cathode setup.