Abstract: The disclosure relates to an electronic beam machining system. The system includes a vacuum chamber; an electron gun located in the vacuum chamber and used to emit electron beam; a holder located in the vacuum chamber and used to fix an object; a control computer; and a diffraction unit located in the vacuum chamber; the diffraction unit includes a two-dimensional nanomaterial; the electron beam transmits the two-dimensional nanomaterial to form a transmission electron beam and a plurality of diffraction electron beams; the transmission electron beam and the plurality of diffraction electron beams radiate the object to form a transmission spot and a plurality of diffraction spots.

Abstract: The disclosure relates to an electronic beam machining system. The system includes a vacuum chamber; an electron gun located in the vacuum chamber and used to emit electron beam; a holder located in the vacuum chamber and used to fix an object; a control computer; and a diffraction unit located in the vacuum chamber; the diffraction unit includes a two-dimensional nanomaterial; the electron beam transmits the two-dimensional nanomaterial to form a transmission electron beam and a plurality of diffraction electron beams; the transmission electron beam and the plurality of diffraction electron beams radiate the object to form a transmission spot and a plurality of diffraction spots.

Abstract: The disclosure relates to a photolithography method based on electronic beam. The method includes: providing an electronic beam; making the electron beam transmit a two dimensional nanomaterial to form a transmission electron beam and a number of diffraction electron beams; shielding the transmission electron beam; and radiating a surface of an object by the plurality of diffraction electron beams. The photolithography method is high efficiency and has low cost.

Abstract: The disclosure relates to a low energy electron microscopy. The electron microscopy includes a vacuum chamber; an electron gun used to emit electron beam; a diffraction chamber; an imaging device; a sample holder used to fix two-dimensional nanomaterial sample; a vacuum pumping device; and a control computer. The electron beam transmits the sample to form a transmission electron beam and diffraction electron beam. The control computer includes a switching module to switch the work mode between a large beam spot diffraction imaging mode and small beam spot diffraction imaging mode.

Abstract: The disclosure relates to a detecting system including a terahertz wave source, a detector and a controlling computer. The terahertz wave source includes a terahertz reflection klystron including an electron emission unit, a resonance unit, an output unit. The electron emission unit is configured to emit electrons. The resonance unit includes a resonant cavity communicated with the electron emission unit so that the electron emission unit emit electrons into the resonant cavity. The resonant cavity of the electron emission unit opposite the cavity wall has an output aperture coupled. The output unit is communicated with the resonance unit by the output aperture coupled. The resonance unit generate terahertz wave transmit to the output unit by the output aperture coupled.

Abstract: The disclosure relates to a low energy electron microscopy. The electron microscopy includes a vacuum chamber; an electron gun used to emit electron beam; a diffraction chamber; an imaging device; a sample holder used to fix two-dimensional nanomaterial sample; a vacuum pumping device; and a control computer. The electron beam transmits the sample to form a transmission electron beam and diffraction electron beam. The control computer includes a switching module to switch the work mode between a large beam spot diffraction imaging mode and small beam spot diffraction imaging mode.

Abstract: The disclosure relates to an electronic beam machining system. The system includes a vacuum chamber; an electron gun located in the vacuum chamber and used to emit electron beam; a holder located in the vacuum chamber and used to fix an object; a control computer; and a diffraction unit located in the vacuum chamber; the diffraction unit includes a two-dimensional nanomaterial; the electron beam transmits the two-dimensional nanomaterial to form a transmission electron beam and a plurality of diffraction electron beams; the transmission electron beam and the plurality of diffraction electron beams radiate the object to form a transmission spot and a plurality of diffraction spots.

Abstract: The disclosure relates to a method for characterizing a two-dimensional nanomaterial sample. The two-dimensional nanomaterial sample is placed in a vacuum chamber. An electron beam passes through the two-dimensional nanomaterial sample to form a diffraction electron beam and a transmission electron beam to form an image on an imaging device. An angle ? between the diffraction electron beam and the transmission electron is obtained. A lattice period d of the two-dimensional nanomaterial sample is calculated according to a formula d sin ??d?=?, where ? represents a wavelength of the electron beam.

Abstract: The disclosure relates to a photolithography method based on electronic beam. The method includes: providing an electronic beam; making the electron beam transmit a two dimensional nanomaterial to form a transmission electron beam and a number of diffraction electron beams; shielding the transmission electron beam; and radiating a surface of an object by the plurality of diffraction electron beams. The photolithography method is high efficiency and has low cost.

Abstract: The disclosure relates to a detecting system including a terahertz wave source, a detector and a controlling computer. The terahertz wave source includes a terahertz reflection klystron including an electron emission unit, a resonance unit, an output unit. The electron emission unit is configured to emit electrons. The resonance unit includes a resonant cavity communicated with the electron emission unit so that the electron emission unit emit electrons into the resonant cavity. The resonant cavity of the electron emission unit opposite the cavity wall has an output aperture coupled. The output unit is communicated with the resonance unit by the output aperture coupled. The resonance unit generate terahertz wave transmit to the output unit by the output aperture coupled.

Abstract: A Tera Hertz reflex klystron includes an electron emission unit, a resonant unit and an output unit. The electron emission is used to emit a plurality of electrons. The electron emission unit defines a first opening. The resonant unit comprises a resonant cavity frame. The resonant cavity frame comprises a top wall and a bottom wall and defines a resonant cavity. The top wall and the bottom wall faces with each other. The bottom wall comprises a bottom opening. The top wall comprises a top opening and at least one outputting hole. The bottom opening and the first opening are merged with each other. The output unit being configured to output Tera Hertz waves. The plurality of electrons are transferred to the output unit from the at least one outputting hole.

Abstract: A Tera Hertz reflex klystron includes an electron emission unit, a resonant unit and an output unit. The electron emission is used to emit a plurality of electrons. The electron emission unit defines a first opening. The resonant unit comprises a resonant cavity frame. The resonant cavity frame comprises a top wall and a bottom wall and defines a resonant cavity. The top wall and the bottom wall faces with each other. The bottom wall comprises a bottom opening. The top wall comprises a top opening and at least one outputting hole. The bottom opening and the first opening are merged with each other. The output unit being configured to output Tera Hertz waves. The plurality of electrons are transferred to the output unit from the at least one outputting hole.

Abstract: The disclosure relates to a field emission cathode. The field emission cathode includes a microchannel plate, a cathode electrode and a number of cathode emitters. The microchannel plate is an insulative plate and includes a first surface and a second surface opposite to the first surface. The microchannel plate defines a number of holes extending through the microchannel plate from the first surface to the second surface. The cathode electrode is located on the first surface. The number of cathode emitters are filled in the number of holes and electrically connected with the cathode electrode.

Abstract: An electron emission source includes a first electrode, a semiconductor layer, an insulating layer, and a second electrode stacked in that sequence, wherein an electron collection layer is sandwiched between the semiconductor layer and the insulating layer, the electron collection layer is in contact with the semiconductor layer and the insulating layer, and the electron collection layer is a conductive layer to collect electrons.

Abstract: An electron emission device includes a number of electron emission units spaced from each other, wherein each of the number of electron emission units includes a first electrode, a semiconductor layer, an electron collection layer, an insulating layer, and a second electrode stacked with each other, the electron collection layer is in contact with the semiconductor layer and the insulating layer, and the electron collection layer is a conductive layer.

Abstract: An electron emission source includes a first electrode, a semiconductor layer, an insulating layer, and a second electrode stacked in that sequence, wherein the semiconductor layer defines a number of holes, the first electrode comprises a carbon nanotube layer, and a portion of the carbon nanotube layer corresponding to the number of holes is suspended on the number of holes.

Abstract: An electron emission device includes a number of electron emission units spaced from each other, wherein each of the number of electron emission units includes a first electrode, a semiconductor layer, an insulating layer, and a second electrode stacked with each other, the first electrode includes a carbon nanotube layer, a number of holes defines in the semiconductor layer, and a portion of the carbon nanotube layer suspended on the number of holes.

Abstract: An electron emission device includes a number of electron emission units, wherein each of the number of electron emission units includes a first electrode, an insulating layer, and a second electrode stacked in that sequence, wherein the first electrode is a carbon nanotube composite structure having a carbon nanotube layer and a semiconductor layer stacked together, and the semiconductor layer is sandwiched between the carbon nanotube layer and the insulating layer, the first electrodes in the number of electron emission units are spaced apart from each other, and the second electrodes in the number of electron emission units are spaced apart from each other.

Abstract: An electron emission source includes a first electrode, an insulating layer, and a second electrode stacked in that sequence, wherein the first electrode is a carbon nanotube composite structure comprising a carbon nanotube layer and a semiconductor layer stacked together, and the semiconductor layer is sandwiched between the carbon nanotube layer and the insulating layer. A method for making the electron emission source is also related.

Abstract: An electron emission device includes a number of second electrodes intersected with a number of first electrodes to define a number of intersections. The first electrode includes a carbon nanotube layer and a semiconductor layer coated on the carbon nanotube layer. An insulating layer is sandwiched between the first electrode and the second electrode at each of the number of intersections, wherein the semiconductor layer is sandwiched between the insulating layer and the carbon nanotube layer.