Abstract: Examples include a photoelectric film that emits electrons by irradiation of an excitation light, an extraction electrode for extracting emitted electrons, and a differential exhaust diaphragm through which extracted electrons pass. A control unit controls an electric field formed in relation to the extraction electrode to make the extracted electrons pass through the differential exhaust diaphragm both in a first case in which the excitation light is irradiated to a first position of the photoelectric film, and in a second case in which the excitation light is irradiated to a second position different from the first position of the photoelectric film.

Abstract: In an axisymmetric electron gun structure, a part of gas molecules flowing from a vacuum chamber having relatively low vacuum reach a photoelectric film, causing problems of deterioration of an NEA surface, instability of an emission current, and a reduction in life of the photoelectric film. An electron microscope including an excitation light source; a photoelectric film formed on a transparent substrate; a condensing lens configured to condense excitation light to the photoelectric film; an anode electrode configured to accelerate an electron beam that is generated when the excitation light is condensed and irradiated to the photoelectric film; a first differential exhaust diaphragm provided close to the photoelectric film and having a passage hole off an axis; a second differential exhaust diaphragm provided close to a sample and having a passage hole on an optical axis; and a deflector for trajectory control of the electron beam.

Abstract: An activation mechanism is provided in an activation region of an electron gun, and includes a light source device 3 configured to irradiate a photocathode with excitation light, a heat generating element, an oxygen generation unit configured to generate oxygen by heating the heat generating element, and an emission current meter configured to monitor an emission current generated by electron emission when the photocathode 1 is irradiated with the excitation light from the light source device. In a surface activation process, the photocathode is irradiated with the excitation light from the light source device, an emission current amount of the photocathode is monitored by the emission current meter, the heat generating element is heated to generate oxygen by the oxygen generation unit, and the heating of the heat generating element is stopped when the emission current amount of the photocathode satisfies a predetermined stop criterion.

Abstract: The apparatus includes: a photocathode including a substrate and a photoelectric film formed on the substrate; a light source configured to emit a pulsed excitation light; a condenser lens facing the substrate of the photocathode and configured to condense the pulsed excitation light toward the photocathode; a first anode electrode and a second anode electrode facing the photoelectric film of the photocathode; a first power supply configured to apply a first control voltage between the first anode electrode and the second anode electrode; and a second power supply configured to apply an acceleration voltage between the photocathode and the second anode electrode. The first anode electrode is disposed between the photocathode and the second anode electrode. A surface of the first anode electrode facing the second anode electrode has a recessed shape, and a surface of the second anode electrode facing the first anode electrode has a protruding shape.

Abstract: The electron gun is provided with a first anode electrode and a second anode electrode to generate an acceleration and deceleration electric field. A lens electric field makes it possible to irradiate a sample with an electron beam emitted from a part outside an optical axis of the photoelectric film without being blocked by a differential exhaust diaphragm. A wide range of electron beams off-optical axis can be used even in a high-brightness photocathode that requires high vacuum. As a result, the photoelectric film and the electron gun can be extended in life, can be stabilized, and can be increased in brightness. Further, it is possible to facilitate a control of emitting electron beams from a plurality of positions on the photoelectric film, a timing control of emitting electron beams from a plurality of positions, a condition control of an electron beam in an electron microscope using electron beams.

Abstract: An electron beam emitted from a photoexcited electron gun is increased in luminance. An electron gun 15 includes: a photocathode 1 including a substrate 11 and a photoelectric film 10; a light source 7 that emits pulsed excitation light; a condenser lens 2 that focuses the pulsed excitation light toward the photocathode; and an extractor electrode 3 that faces the photocathode and that accelerates an electron beam generated from the photoelectric film by focusing the pulsed excitation light by the condenser lens, transmitting the pulsed excitation light through the substrate of the photocathode, and causing the pulsed excitation light to be incident on the photocathode. The pulsed excitation light is condensed at different timings at different positions on the photoelectric film of the photocathode.

Abstract: A light source that emits pulse excitation light includes a laser light source, an optical splitter that splits a pulse laser beam into a plurality of pulse laser beams, phase adjusters and optical amplifiers provided for the pulse laser beams, and an optical combiner that combines the plurality of pulse laser beams whose phases are adjusted and that are amplified, and outputs combined light as the pulse excitation light. An optical phase controller controls phase delay amounts of the phase adjusters, and an optical monitor detects an inclination of the pulse excitation light relative to an optical axis of a focusing lens. The optical phase controller stores phase delay amount data indicating phase delay amounts of the plurality of phase adjusters in which the inclination is a predetermined value, and sets the phase delay amounts of the plurality of phase adjusters based on the phase delay amount data.

Abstract: An object of the invention is to provide an electron microscope capable of obtaining a sufficient energy resolution without forming a long drift space and capable of attaining high energy discrimination detection performance with approximately the same device size as in the related art. The electron microscope according to the invention includes a pulsed electron emission mechanism configured to emit an electron beam in a pulsed manner, and discriminates energy of signal electrons by discriminating the signal electrons, which are emitted from a sample by irradiating the sample with the electron beam, according to a time of flight (see FIG. 2).

Abstract: An electron beam emitted from a photoexcited electron gun is increased in luminance. An electron gun 15 includes: a photocathode 1 including a substrate 11 and a photoelectric film 10; a light source 7 that emits pulsed excitation light; a condenser lens 2 that focuses the pulsed excitation light toward the photocathode; and an extractor electrode 3 that faces the photocathode and that accelerates an electron beam generated from the photoelectric film by focusing the pulsed excitation light by the condenser lens, transmitting the pulsed excitation light through the substrate of the photocathode, and causing the pulsed excitation light to be incident on the photocathode. The pulsed excitation light is condensed at different timings at different positions on the photoelectric film of the photocathode.

Abstract: The apparatus includes: a photocathode including a substrate and a photoelectric film formed on the substrate; a light source configured to emit a pulsed excitation light; a condenser lens facing the substrate of the photocathode and configured to condense the pulsed excitation light toward the photocathode; a first anode electrode and a second anode electrode facing the photoelectric film of the photocathode; a first power supply configured to apply a first control voltage between the first anode electrode and the second anode electrode; and a second power supply configured to apply an acceleration voltage between the photocathode and the second anode electrode. The first anode electrode is disposed between the photocathode and the second anode electrode. A surface of the first anode electrode facing the second anode electrode has a recessed shape, and a surface of the second anode electrode facing the first anode electrode has a protruding shape.

Abstract: An activation mechanism is provided in an activation region of an electron gun, and includes a light source device 3 configured to irradiate a photocathode with excitation light, a heat generating element, an oxygen generation unit configured to generate oxygen by heating the heat generating element, and an emission current meter configured to monitor an emission current generated by electron emission when the photocathode 1 is irradiated with the excitation light from the light source device. In a surface activation process, the photocathode is irradiated with the excitation light from the light source device, an emission current amount of the photocathode is monitored by the emission current meter, the heat generating element is heated to generate oxygen by the oxygen generation unit, and the heating of the heat generating element is stopped when the emission current amount of the photocathode satisfies a predetermined stop criterion.

Abstract: A scanning electron beam apparatus which two-dimensionally scans a sample by an electron beam to achieve high resolution even with a photoexcited electron source. The electron beam apparatus includes a photocathode including a substrate having a refractive index of more than 1.7 and a photoemissive film, a focusing lens configured to focus an excitation light toward the photocathode, an extractor electrode disposed facing the photocathode and configured to accelerate an electron beam generated from the photoemissive film by focusing the excitation light by the focusing lens and emitting the excitation light through the substrate, and an electron optics including a deflector configured to two-dimensionally scan a sample by the electron beam accelerated by the extractor electrode. For a spherical aberration of the focusing lens, a root mean square of the spherical aberration on the photoemissive film is equal to or less than 1/14 of a wavelength of the excitation light.

Abstract: The electron gun is provided with a first anode electrode and a second anode electrode to generate an acceleration and deceleration electric field. A lens electric field makes it possible to irradiate a sample with an electron beam emitted from a part outside an optical axis of the photoelectric film without being blocked by a differential exhaust diaphragm. A wide range of electron beams off-optical axis can be used even in a high-brightness photocathode that requires high vacuum. As a result, the photoelectric film and the electron gun can be extended in life, can be stabilized, and can be increased in brightness. Further, it is possible to facilitate a control of emitting electron beams from a plurality of positions on the photoelectric film, a timing control of emitting electron beams from a plurality of positions, a condition control of an electron beam in an electron microscope using electron beams.

Abstract: A scanning electron beam apparatus which two-dimensionally scans a sample by an electron beam, to achieve high resolution even with a photoexcited electron source. The electron beam apparatus includes a photocathode including a substrate having a refractive index of more than 1.7 and a photoemissive film, a focusing lens configured to focus an excitation light toward the photocathode, an extractor electrode disposed facing the photocathode and configured to accelerate an electron beam generated from the photoemissive film by focusing the excitation light by the focusing lens and emitting the excitation light through the substrate, and an electron optics including a deflector configured to two-dimensionally scan a sample by the electron beam accelerated by the extractor electrode. For a spherical aberration of the focusing lens, a root mean square of the spherical aberration on the photoemissive film is equal to or less than 1/14 of a wavelength of the excitation light.

Abstract: To provide an electron microscope capable of performing the switching-over between normal illumination and annular illumination, wide-area irradiation, an interference pattern as desired or normal illumination in an expeditious and readily manner or achieving a better S/N ratio, the electron microscope comprises a photocathode 101 with negative electron affinity in use; an excitation optical system to excite the photocathode; and an electron optics system to irradiate an electron beam 13 generated from the photocathode by excitation light 12 irradiated through the excitation optical system onto a sample, the excitation optical system including a light source device 107 for the excitation light; and an optical modulation means 108 which is disposed in an optical path of the excitation light to perform spatial phase modulation to the excitation light.

Abstract: To provide an electron microscope capable of performing the switching-over between normal illumination and annular illumination, wide-area irradiation, an interference pattern as desired or normal illumination in an expeditious and readily manner or achieving a better S/N ratio, the electron microscope comprises a photocathode 101 with negative electron affinity in use; an excitation optical system to excite the photocathode; and an electron optics system to irradiate an electron beam 13 generated from the photocathode by excitation light 12 irradiated through the excitation optical system onto a sample, the excitation optical system including a light source device 107 for the excitation light; and an optical modulation means 108 which is disposed in an optical path of the excitation light to perform spatial phase modulation to the excitation light.

Abstract: To provide an electron microscope capable of performing the switching-over between normal illumination and annular illumination, wide-area irradiation, an interference pattern as desired or normal illumination in an expeditious and readily manner or achieving a better S/N ratio, the electron microscope comprises a photocathode 101 with negative electron affinity in use; an excitation optical system to excite the photocathode; and an electron optics system to irradiate an electron beam 13 generated from the photocathode by excitation light 12 irradiated through the excitation optical system onto a sample, the excitation optical system including a light source device 107 for the excitation light; and an optical modulation means 108 which is disposed in an optical path of the excitation light to perform spatial phase modulation to the excitation light.

Abstract: An electron source that can be used stably for a long time even when hexaboride is used, and an electron beam device using the electron source are provided. The invention is directed to an electron source which includes a filament made of a metal, a metal tube that is fixed to the filament and has a plurality of recesses disposed at least in two axial directions so as to surround a central axis at an outer periphery, and a columnar hexaboride tip that emits an electron, is disposed so as to protrude from the inside of the metal tube to a side opposite to the filament, and is in contact with a bottom of each of the plurality of recesses of the metal tube.

Abstract: In order to provide a stable hexaboride single-crystal field emission electron source capable of heat-flashing, this field emission electron source is provided with a metal filament, a metal tube joined thereto, a hexaboride tip that emits electrons, and graphite sheets that are independent of the metal tube and the hexaboride tip. The hexaboride tip is arranged so as not to be in structural contact with the metal tube due to the graphite sheets. The hexaboride tip, the graphite sheets, and the metal tube are configured so as to be mechanically and electrically in contact with one another.

Abstract: An electron source that can be used stably for a long time even when hexaboride is used, and an electron beam device using the electron source are provided. The invention is directed to an electron source which includes a filament made of a metal, a metal tube that is fixed to the filament and has a plurality of recesses disposed at least in two axial directions so as to surround a central axis at an outer periphery, and a columnar hexaboride tip that emits an electron, is disposed so as to protrude from the inside of the metal tube to a side opposite to the filament, and is in contact with a bottom of each of the plurality of recesses of the metal tube.