Provided is a field emission apparatus including a pipe-shaped emitter holder comprising an electrically conductive material and a first internal space communicated in a first direction, and an emitter electrode having one or more yarns each having a structure extending in the first direction in which a plurality of CNTs that extend in the first direction are aggregated, and the emitter electrode is inserted in the first internal space while extending in the first direction.

A method for making a carbon nanotube field emitter is provided. A carbon nanotube film is dealed with a carbon nanotube film in a circumstance with a temperature ranged from 1400 to 1800 C. and a pressure ranged from 40 to 60 MPa to form at least one first carbon nanotube structure. The at least one first carbon nanotube structure is heated to graphitize the at least one first carbon nanotube structure to form at least one second carbon nanotube structure. At least two electrodes is welded to fix one end of the at least one second carbon nanotube structure between adjacent two electrodes to form a field emission preparation body. The field emission preparation body has a emission end. The emission end is bonded to form a carbon nanotube field emitter.

A method for making a carbon nanotube field emitter is provided. A carbon nanotube film is dealed with a carbon nanotube film in a circumstance with a temperature ranged from 1400 to 1800 C. and a pressure ranged from 40 to 60 MPa to form at least one first carbon nanotube structure. The at least one first carbon nanotube structure is heated to graphitize the at least one first carbon nanotube structure to form at least one second carbon nanotube structure. At least two electrodes is welded to fix one end of the at least one second carbon nanotube structure between adjacent two electrodes to form a field emission preparation body. The field emission preparation body has a emission end. The emission end is bonded to form a carbon nanotube field emitter.

The present invention relates to a portable carbon nanotube- and filament-type X-ray apparatus and a method for controlling same. The present invention comprises: a control unit for controlling a portable carbon nanotube- and filament-type X-ray apparatus; and a high-voltage apparatus, of an X-ray source, which is connected to the control unit, has carbon nanotubes (CNT) applied to the high-voltage apparatus of the X-ray source, enables a low-dose exposure by means of detailed control, enables significant reduction of power consumption due to omission of filaments, and has a high-voltage capacitor and a high-voltage diode structure disposed in a sandwiched structure such that the size of the high-voltage apparatus is reduced. The present invention, which is characterized as above, provides improved image quality, assurance of long life, low power consumption, battery-less characteristic, rapid charging, a compact and lightweight structure, enhanced operability and stable exposure measures for an X-ray apparatus used mostly for dental purposes. Therefore, the present invention greatly enhances the reliability of the X-ray apparatus, thereby satisfying various user needs and creating a positive image.

Provided is an infrared optical sensor including a substrate, a channel layer on the substrate, optical absorption structures dispersed and disposed on the channel layer, and electrodes disposed on the substrate, and disposed on both sides of the channel layer, wherein the channel layer and the optical absorption structures include transition metal dichalcogenides.

A tomosynthesis system has an x-ray source with an addressable array of electron emitting sections on the cathode. The x-ray source moves rotationally about an imaging target, such as a breast. During the rotation, x-rays are emitting from the x-ray source while the x-ray source continues to move. During the emission of x-rays, different subsets of electron-emitting sections of the addressable array are activated to compensate for movement of the x-ray source. By activating the different subsets of electron-emitting sections, an effective focal spot of the x-ray position appears to retain the same shape, size, and position from the perspective of the imaging target, despite movement of the x-ray source itself.

Provided is a field emission device. The field emission device includes a cathode electrode having a first surface and a second surface facing the first surface, the cathode electrode including grooves that are recessed from the first surface toward the second surface, the grooves extending in a first direction parallel to the first surface and emitter structures which are disposed within the grooves and each of which includes a core extending in the first direction and a conductive wire configured to surround the core. The grooves may be arranged in a second direction crossing the first direction, and the emitter structures may be disposed at vertical levels different from each other.

A C-arm X-ray apparatus includes an x-ray emitter (5) and an X-ray detector (4) which are maintained on a C-arm (2) mounted on a reference plane. The x-ray emitter (5) has nanorods as electron emitters and has an elongated structure which is at least partially aligned along a surface normal of the reference plane.

An electron beam source is provided that includes a vessel forming a chamber, a cathode disposed within the chamber, the cathode comprising a low dimensional electrically conductive material having an anisotropic restricted thermal conductivity, an electrode disposed in the chamber, the electrode being connectable to a power source for applying a positive voltage to the electrode relative to the cathode for accelerating free electrons away from the cathode to form an electron beam when the cathode is illuminated by electromagnetic (EM) radiation such that the cathode thermionically emits free electrons, and an electron emission window in the chamber for passing a generated electron beam out of the chamber. An electron microscope that incorporates the electron beam source is also provided.

Provided is a field emission device. The field emission device includes a cathode electrode having a first surface and a second surface facing the first surface, the cathode electrode including grooves that are recessed from the first surface toward the second surface, the grooves extending in a first direction parallel to the first surface and emitter structures which are disposed within the grooves and each of which includes a core extending in the first direction and a conductive wire configured to surround the core. The grooves may be arranged in a second direction crossing the first direction, and the emitter structures may be disposed at vertical levels different from each other.