Described herein is an x-ray backscatter apparatus for non-destructive inspection of a part. The apparatus includes an x-ray emitter and a zone plate. The x-ray emitter includes an x-ray shield, a vacuum tube, a cathode, and an anode. The x-ray shield has an emission aperture. The vacuum tube is within the x-ray shield. The cathode and anode are enclosed within the vacuum tube. The cathode generates an electron emission. The anode is located relative to the cathode to receive the electron emission and convert the electron emission to a hard x-ray emission and is located relative to the emission aperture to direct at least a portion of the hard x-ray emission through the emission aperture. The zone plate is external to the x-ray shield and located relative to the emission aperture to receive the portion of the hard x-ray emission and focus the portion into a focused hard x-ray emission.

A method for increasing the MeV hot electron yield and secondary radiation produced by short-pulse laser-target interactions with an appropriately high or low atomic number (Z) target. Secondary radiation, such as MeV x-rays, gamma-rays, protons, ions, neutrons, positrons and electromagnetic radiation in the microwave to sub-mm region, can be used, e.g., for the flash radiography of dense objects.

A method of generating X-rays includes providing a field-emission diode including two electrodes separated by a gap, a first conductor, a first insulator on a surface of the first conductor, a second insulator on a surface of the first insulator that is not in contact with the first conductor, and a second conductor. The first insulator and the second insulator have trapped electrons at an interface therebetween, and are provided between the first conductor and the second conductor. The method further includes moving the second conductor with respect to the first conductor to induce electrons on the second conductor via electrostatic induction; accelerating the induced electrons across the gap of the field-emission diode; and striking a target with accelerated electrons to produce an X-ray. The first insulator and the second insulator are not the same.

A method of designing an x-ray emitter panel 100 including the step of determining a pitch scale, r, to be used in placing x-ray emitter elements 110 on the panel 100, thereby arriving at a specific design of x-ray emitter panel 100 suitable for a specific use.

For each X-ray path through a tissue, numerous trials are conducted. In each trial, X-ray photons are emitted along the path until a Geiger-mode avalanche photodiode clicks. A temporal averagei.e., the average amount of time elapsed before a click occursis calculated. This temporal average is, in turn, used to estimate a causal intensity of X-ray light that passes through the tissue along the path and reaches the diode. Based on the causal intensities for multiple paths, a computer generates computed tomography (CT) images or 2D digital radiographic images. The causal intensities used to create the images are estimated from temporal statistics, and not from conventional measurements of intensity at a pixel. X-ray dosage needed for imaging is dramatically reduced as follows: a click of the photodiode triggers negative feedback that causes the system to halt irradiation of the tissue along a path, until the next trial begins.

An X-ray source for ionizing of gases includes a field emission tip array within a vacuum region enclosed by a hood and a part of a support plate. The field emission tip array is arranged electrically insulated with respect to the carrier plate and wired as a cathode connected to a high-voltage source. A transmission window transparent to X-ray radiation is arranged in the hood centrally above the field emission tip array, and the hood is wired as an anode.

The present disclosure provides a method of manufacturing a carbon nanotube electron emitter, including: forming a carbon nanotube film; performing densification by dipping the carbon nanotube film in a solvent; cutting an area of the carbon nanotube film into a pointed shape or a line shape; and fixing the cutting area of the carbon nanotube film arranged between at least two metal members to face upwards with lateral pressure.

A computer tomograph (1) for mammographic x-ray imaging includes a MBFEX tube (20) and a flat-bed x-ray detector (30). Cathodes (40) are arranged in a fixed manner in rows in the MBFEX tube (20), the cathodes (40) being provided for the field emission of electrons. Geometry, radiation density and wavelength range of an x-ray beam (b) can be set. The MBFEX tube (20) is movable parallel (z) to the flat-bed x-ray detector (30). The flat bed x-ray detector (30) includes a moveable x-ray screen (31), the opening of which can be set. Using the x-ray screen (31), an imaging area (A) on the detector surface (D) of the flat-bed x-ray detector (30) can be selected and moved. Compared to conventional computer tomographs having rotating x-ray components, the computer tomograph (1) has a lighter and more compact design, with which a particularly small focal spot size is achieved.

Disclosed is an X-ray source, including: a cathode; an anode positioned on the cathode so as to face the cathode; emitters formed on the cathode; a gate electrode positioned between the cathode and the anode and including openings at positions corresponding to those of the emitters; an insulating spacer formed between the gate and the anode; and a coating layer formed on an internal wall of the insulating spacer, and including a material having a lower secondary electron emission coefficient than that of the insulating spacer.

An x-ray tube casing is provided which includes a central frame having internal passages to supply a cooling fluid directly to the casing without the need for an external dedicated heat exchanger. The cooling fluid flowing through the passages in the easing can thermally contact the dielectric coolant within the casing to cool the tube coolant during operation of the x-ray tube. The casing is formed in an additive manufacturing process to allow for tight tolerances with regard to the structure for the casing and the internal passages to reduce the size and weight of the casing. The casing can additionally be formed from a metal matrix including a metal with high x-ray attenuation and a filler metal. The metal matrix eliminates the need for a separate x-ray attenuation layer within the casing, further reducing the size, number of parts and assembly complexity of the casing.