Abstract: An electron emitter according to one or more example embodiments for a rotary piston X-ray tube has a segmented emitter surface including at least two emitter elements which can be activated independently of each other and is set up to activate at least one subset of the segments of the segmented emitter surface as an activated emission surface for emitting electrons from the activated emission surface, wherein the at least two emitter elements are arranged in such a way that the segmented emitter surface is axially symmetrical in an emitter surface place, at least one emitter element of the at least two emitter elements is embodied for the thermionic emission of electrons, and the at least two emitter elements are arranged such that a distance between the respective emitter surfaces is minimal.

Abstract: One or more example embodiments relates to a cathode device and an X-ray source. The cathode device for an X-ray source has an electron emitter including a plurality of field effect emitter elements aligned in parallel to form an emission surface on the upper side of the plurality of field effect emitter elements aligned in parallel a gate electrode, arranged above the emission surface, a multiple first contact elements for at least two independently current-carrying current paths of the electron emitter, electrons from at least one of the current paths are emittable depending on an emission voltage between the gate electrode and the emission surface via the field effect emitter elements; and an emitter seat including multiple second contact elements, the multiple second contact elements connectable with the multiple first contact elements for closing the current paths.

Abstract: An X-ray tube has a tube body, which encloses a tube volume in a gas-tight manner. An emitter electrode, a gate electrode and an anode are arranged within the tube volume. The emitter electrode is embodied as an unheated electrode which has a plurality of emitter needles arranged on a substrate in a region facing the gate electrode. The gate electrode is divided into a main region and a number of additional regions by insulating structures introduced into the gate electrode. An emission voltage is applied to the main region relative to the emitter electrode. The additional regions are electrically conductively connected to the main region only by way of connecting bridges. At least one cutout of the gate electrode is arranged in the additional regions in each case.

Abstract: A field-effect emitter microstructure for an X-ray tube has an emitter needle, a gate electrode with a gate opening, a first insulating layer, wherein free electrons can be produced in the field-effect emission segment via an emission voltage which can be applied between the gate electrode and the field-effect emission segment. A lower side of a second insulating layer at least partially abuts an upper side of the gate electrode, an upper side of the second insulating layer at least partially abuts a lower side of a focusing layer, and the second insulating layer and the focusing layer each have a through-opening for the free electrons.

Abstract: A field effect emitter microstructure comprises: an emitter needle having a field effect emitter portion on a first end; a gate electrode with a gate opening connecting an underside of the gate electrode facing the emitter needle to an upper side of the gate electrode facing away from the underside, wherein a central axis of the emitter needle is perpendicular to the gate electrode toward the gate opening in the emitting direction; and a first insulating layer adjoining the emitter needle under the field effect emitter portion and at least partially adjoining the gate electrode underside. An emission voltage is applied to produce free electrons in the field effect emitter portion. The first end of the emitter needle has a protrusion greater than or equal to zero relative to the gate electrode upper side and/or the first insulating layer adjoins the inner wall of the gate opening.

Abstract: A method for reducing electron emission of an electron emitter comprises: emitting electrons from a first current path via at least one first field effect emitter element, subject to an emission voltage between a gate electrode and an emission surface; determining a property of the first current path; and activating a first current limiting unit subject to the properties of the first current path to reduce the electron emission of the electron emitter.

Abstract: One or more example embodiments relates to a cathode device and an X-ray source. The cathode device for an X-ray source has an electron emitter including a plurality of field effect emitter elements aligned in parallel to form an emission surface on the upper side of the plurality of field effect emitter elements aligned in parallel a gate electrode, arranged above the emission surface, a multiple first contact elements for at least two independently current-carrying current paths of the electron emitter, electrons from at least one of the current paths are emittable depending on an emission voltage between the gate electrode and the emission surface via the field effect emitter elements; and an emitter seat including multiple second contact elements, the multiple second contact elements connectable with the multiple first contact elements for closing the current paths.

Abstract: One or more example embodiments relates to a cathode device and an X-ray source. The cathode device for an X-ray source has an electron emitter including a plurality of field effect emitter elements aligned in parallel to form an emission surface on the upper side of the plurality of field effect emitter elements aligned in parallel a gate electrode, arranged above the emission surface, a multiple first contact elements for at least two independently current-carrying current paths of the electron emitter, electrons from at least one of the current paths are emittable depending on an emission voltage between the gate electrode and the emission surface via the field effect emitter elements; and an emitter seat including multiple second contact elements, the multiple second contact elements connectable with the multiple first contact elements for closing the current paths.

Abstract: A method for reducing electron emission of an electron emitter comprises: emitting electrons from a first current path via at least one first field effect emitter element, subject to an emission voltage between a gate electrode and an emission surface; determining a property of the first current path; and activating a first current limiting unit subject to the properties of the first current path to reduce the electron emission of the electron emitter.

Abstract: One or more example embodiments relates to an extra-focal beam aperture device for an X-ray emitter and to the X-ray emitter. The extra-focal beam aperture device according to one or more example embodiments for an X-ray emitter has a planar beam-shaping element including an X-ray opaque material, the planar beam-shaping element being configured to form a useful X-ray beam and an X-ray measuring beam separate from the useful X-ray beam, from an X-ray beam bundle incident upon the extra-focal beam aperture device, the planar beam-shaping element including two side faces opposite each other, a radial lateral surface between the two side faces, a cross-section through the radial lateral surface having an approximately trapezoid shape, and at least one cut-out for shaping the X-ray measuring beam, the at least one cut-out having a tapering cross-section.

Abstract: One or more example embodiments relates to an extra-focal beam aperture device for an X-ray emitter and to the X-ray emitter. The extra-focal beam aperture device according to one or more example embodiments for an X-ray emitter has a planar beam-shaping element including an X-ray opaque material, the planar beam-shaping element being configured to form a useful X-ray beam and an X-ray measuring beam separate from the useful X-ray beam, from an X-ray beam bundle incident upon the extra-focal beam aperture device, the planar beam-shaping element including two side faces opposite each other, a radial lateral surface between the two side faces, a cross-section through the radial lateral surface having an approximately trapezoid shape, and at least one cut-out for shaping the X-ray measuring beam, the at least one cut-out having a tapering cross-section.

Abstract: An electron emitter according to one or more example embodiments for a rotary piston X-ray tube has a segmented emitter surface including at least two emitter elements which can be activated independently of each other and is set up to activate at least one subset of the segments of the segmented emitter surface as an activated emission surface for emitting electrons from the activated emission surface, wherein the at least two emitter elements are arranged in such a way that the segmented emitter surface is axially symmetrical in an emitter surface place, at least one emitter element of the at least two emitter elements is embodied for the thermionic emission of electrons, and the at least two emitter elements are arranged such that a distance between the respective emitter surfaces is minimal.

Abstract: A field effect electron emitter comprises a segmented emission surface and a control unit. The segmented emission surface has a plurality of field effect emitter needles and a number of segments, each segment having an activatable part emission surface, wherein the plurality of field effect emitter needles are distributed on the activatable part emission surfaces. The control unit is configured to activate various groups with at least one of the number of segments for a simultaneous electron emission from respective activatable part emission surfaces such that coherent and grouped part emission surfaces able to be activated in succession overlap in pairs by at least 25%.

Abstract: At least one example embodiment provides an electron emitter apparatus having a first ring of field-effect emitter needles, the field-effect emitter needles of the first ring forming a first emitter surface on an inner side of the first ring; and a second ring of field-effect emitter needles, the field-effect emitter needles of the second ring forming a second emitter surface on an inner side of the second ring, wherein the first ring and the second ring are arranged in such that the first emitter surface and the second emitter surface form a substantially contiguous three-dimensional overall emitter surface, the substantially contiguous three-dimensional overall emitter surface defining a hollow channel along a longitudinal axis of the electron emitter apparatus.

Abstract: Some example embodiments provide an x-ray tube for a stereoscopic imaging having an evacuated x-ray tube housing; an electron emitter apparatus in the x-ray tube housing, the electron emitter apparatus including a first field effect emitter with a first emitter surface and a second field effect emitter with a second emitter surface, at least one of the first emitter surface or the second emitter surface being segmented such that a portion of the at least one of the first emitter surface or the second emitter surface can be set relative to the respective overall emitter surface by selectively switching emitter segments of the at least one of the first emitter surface or the second emitter surface; an anode unit in the x-ray tube housing, the anode unit configured to generate x-ray radiation for the stereoscopic imaging as a function of electrons striking two focal points; and a control unit.

Abstract: An x-ray anode for an x-ray emitter has a structured surface provided for impingement with electrons. According to an embodiment of the invention, the structured surface has a surface structure which alternates periodically at least in sections and which varies in the micrometer range with respect to its depth extension and periodicity.

Abstract: Some example embodiments provide an x-ray tube for a stereoscopic imaging having an evacuated x-ray tube housing; an electron emitter apparatus in the x-ray tube housing, the electron emitter apparatus including a first field effect emitter with a first emitter surface and a second field effect emitter with a second emitter surface, at least one of the first emitter surface or the second emitter surface being segmented such that a portion of the at least one of the first emitter surface or the second emitter surface can be set relative to the respective overall emitter surface by selectively switching emitter segments of the at least one of the first emitter surface or the second emitter surface; an anode unit in the x-ray tube housing, the anode unit configured to generate x-ray radiation for the stereoscopic imaging as a function of electrons striking two focal points; and a control unit.

Abstract: At least one example embodiment provides an electron emitter apparatus having a first ring of field-effect emitter needles, the field-effect emitter needles of the first ring forming a first emitter surface on an inner side of the first ring; and a second ring of field-effect emitter needles, the field-effect emitter needles of the second ring forming a second emitter surface on an inner side of the second ring, wherein the first ring and the second ring are arranged in such that the first emitter surface and the second emitter surface form a substantially contiguous three-dimensional overall emitter surface, the substantially contiguous three-dimensional overall emitter surface defining a hollow channel along a longitudinal axis of the electron emitter apparatus.

Abstract: An x-ray tube includes an electron emitter to emit an electron beam; and a multilayer anode including a first anode layer facing the electron beam and a second anode layer facing away from the electron beam. The first anode layer includes a first anode material to generate a braking radiation via the electron beam and the second anode layer includes a second anode material to generate a further x-ray radiation via the braking radiation. The further x-ray radiation is relatively more monochromatic than the braking radiation and wherein the first anode layer and the second anode layer adjoin in a planar manner.

Abstract: An x-ray anode for an x-ray emitter has a structured surface provided for impingement with electrons. According to an embodiment of the invention, the structured surface has a surface structure which alternates periodically at least in sections and which varies in the micrometer range with respect to its depth extension and periodicity.