摘要:
The invention relates the field of electron emitter of an X-ray tube. More specifically the invention relates to flat thermionic emitters to be used in X-ray systems with variable focus spot size and shape. The emitter provides two main terminals (3, 5) which form current conductors and which sup-port at least two emitting portions (7, 9). The emitting portions are structured in a way so that they are electron optical identical or nearly identical increasing the emergency operating options in case of emitter damage.
摘要:
The invention relates the field of electron emitter of an X-ray tube. More specifically the invention relates to flat thermionic emitters to be used in X-ray systems with variable focus spot size and shape. The emitter provides two main terminals (3, 5) which form current conductors and which support at least two emitting portions (7, 9). The emitting portions are structured in a way so that they are electron optical identical or nearly identical increasing the emergency operating options in case of emitter damage.
摘要:
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).
摘要:
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.
摘要:
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.
摘要:
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).
摘要:
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.
摘要:
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.
摘要:
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. The filament frame structure comprises frame surface portions arranged transverse to the emitting direction, and the filament frame structure is held by the support structure.
摘要:
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).