A device and method for creating beam formed X-Ray radiation using radio frequency (RF) modulated field emission X-ray sources is described. A radio frequency RF source generates a RF control signal which is supplied to an array of phase delay elements to generate multiple individually controlled phase delayed RF signals. These are then directly provided to each of a plurality of field emission sources (via a matching circuit) to generate a plurality of RF modulated electron current, or beam, each at the same frequency and phase delay of the phase delayed RF signals. Each of the electron beams impacts a target anode to generate X-rays also at the same frequency and phase delay of the phase delayed RF signals. By controlling each of the phase delay elements a beamformed X-ray radiation pattern can be generated.

A vacuum electron tube comprises at least one electron-emitting cathode and at least one anode arranged in a vacuum chamber, the cathode having a planar structure comprising a substrate comprising a conductive material, a plurality of nanotube or nanowire elements electrically insulated from the substrate, the longitudinal axis of the nanotube or nanowire elements substantially parallel to the plane of the substrate, and at least one first connector electrically linked to at least one nanotube or nanowire element so as to be able to apply a first electrical potential to the nanowire or nanotube element.

A device and method for creating controlled radio frequency (RF) modulated X-ray radiation is described. The device includes an anode housed within a vacuum enclosure which acts to accelerate and convert an electron beam into X-ray radiation. A RF enclosure is housed within the vacuum enclosure and houses a field emission device, such as a carbon nanotube field emission device or similar cold cathode field emission device. The field emission device is biased to emit the electron beam from a field emission cathode via an extraction electrode in the RF enclosure towards the anode. Additionally an RF impedance matching and coupling circuit is connected electrically to the field emission device. The field emission device is thus directly driven with a RF signal to produce an RF modulated electron current to produce an RF modulated X-ray radiation.

A light modulated electron source utilizes a photon-beam source to modulate the emission current of an electron beam emitted from a silicon-based field emitter. The field emitter's cathode includes a protrusion fabricated on a silicon substrate and having an emission tip covered by a coating layer. An extractor generates an electric field that attracts free electrons toward the emission tip for emission as part of the electron beam. The photon-beam source generates a photon beam including photons having an energy greater than the bandgap of silicon, and includes optics that direct the photon beam onto the emission tip, whereby each absorbed photon creates a photo-electron that combines with the free electrons to enhance the electron beam's emission current. A controller modulates the emission current by controlling the intensity of the photon beam applied to the emission tip. A monitor measures the electron beam and provides feedback to the controller.

A micro focus X-ray tube is provided. The micro focus X-ray tube has a bonding structure in which a ceramic and a metal without an exhaust pipe are stacked by using a nano electric field emitter of an excellent feature.

The present invention relates to a rotary anode X-ray source. In addition to a primary cathode of a rotary anode X-ray tube, an auxiliary cathode is provided in the rotary anode X-ray tube. Electrons from the auxiliary cathode are focused into an area on the anode, from which X-rays cannot enter the used X-ray beam generated by the primary cathode. An emission current controlling device is used to control the electron emission of the auxiliary cathode. Thus, the voltage down-ramp for dual energy scanning is kept constant even though the primary X-ray output changes for the sake of dose modulation or during a transient of the primary electron current.

An electron source (2) for generating an electron beam (8) having a cathode (1) and an anode (4) in the form of a graphene layer (6, 12) epitaxially grown on a silicon carbide substrate (5). The invention is suitable for monolithic preparation of a miniaturized source of a high-energy focused electron beam, including its use as an on-chip X-ray source. All components can be prepared from or on a single silicon carbide chip.

A method of manufacturing a CNT paste emitter in accordance with an exemplary embodiment of the present disclosure includes a process of mixing first CNT powder, graphite nanoparticles, SiC nanoparticles, Ni nanoparticles, a dispersant and distilled water and then performing a dispersion process by means of ultrasonication, a process of acquiring second CNT powder by filtering a solution dispersed during the dispersion process, a process of mixing the second CNT powder with a graphite binder and then preparing a CNT paste by means of ball milling, and a process of forming an interface layer on a metal or graphite substrate and then bonding the CNT paste.

It is a CNT device (1) (carbon-metal structure) equipped with a carbon nanotube layer (2) (CNT layer 2; same hereafter) on a metal pedestal (4). The metal pedestal (4) is brazed to the CNT layer (2) with a brazing material layer (3) interposed therebetween. When manufacturing the CNT device (1), firstly, the CNT layer (2) is formed on a heat-resistant textured substrate (6). Next, the metal pedestal (4) is brazed to the CNT layer (2) that is on the heat-resistant textured substrate (6) with the brazing material layer (3) interposed therebetween. Then, the metal pedestal (4) (and the CNT layer 2) is peeled off the heat-resistant textured substrate (6) to transfer the CNT layer (2) from the heat-resistant textured substrate (6) to the metal pedestal (4).

The present invention provides an emitter, which comprises carbon nanotubes and is excellent in the efficiency of electron emission, and an X-ray tube comprising the same.