The present disclosure proposes a crossover-forming deflector array of an electro-optical system for directing a plurality of electron beams onto an electron detection device. The crossover-forming deflector array includes a plurality of crossover-forming deflectors positioned at or at least near an image plane of a set of one or more electro-optical lenses of the electro-optical system, wherein each crossover-forming deflector is aligned with a corresponding electron beam of the plurality of electron beams.

Various methods and systems are provided for aligning zone axis of a sample with an incident beam. As one example, the alignment may be based on a zone axis tilt. The zone axis tilt may be determined based on locations of a direct beam and a zero order Laue zone in the diffraction pattern. The direct beam location may be determined based on diffraction patterns acquired with different incident angles.

To implement a calibration sample by which an incident angle can be measured with high accuracy, an electron beam adjustment method, and an electron beam apparatus using the calibration sample. To adjust an electron beam using a calibration sample, the calibration sample includes a silicon single crystal substrate 201 whose upper surface is a {110} plane, a first recess structure 202 opening in the upper surface and extending in a first direction, and a second recess structure 203 opening in the upper surface and extending in a second direction intersecting the first direction, in which the first recess structure and the second recess structure each include a first side surface and a first bottom surface that intersects the first side surface, and a second side surface and a second bottom surface that intersects the second side surface, the first side surface and the second side surface are {111} planes, and the first bottom surface and the second bottom surface are crystal planes different from the {110} planes.

A charged-particle beam (CPB) is aligned to a primary axis of a CPB microscope by determining a first beam deflection drive to a beam deflector for directing the CPB passing a reference location displaced from the primary axis. The beam deflector is provided with a second beam deflection drive during the working mode of the CPB microscope to propagate the beam along the primary axis. The second beam deflection drive is determined based on the first beam deflection drive.

Variations in charged-particle-beam (CPB) source location are determined by scanning an alignment aperture that is fixed with respect to a beam defining aperture in a CPB, particularly at edges of a defocused CPB illumination disk. The alignment aperture is operable to transmit a CPB portion to a secondary emission surface that produces secondary emission directed to a scintillator element. Scintillation light produced in response is directed out of a vacuum enclosure associated with the CPB via a light guide to an external photodetection system.

When a charged particle beam aperture having an annular shape is used, since a charged particle beam directly above the optical axis having the highest current density in the charged particle beam is blocked, it is difficult to dispose the charged particle beam aperture at an optimal mounting position. An charged particle beam apparatus includes a charged particle beam source that generates a charged particle beam, a charged particle beam aperture, a charged particle beam aperture power supply that applies a voltage to the charged particle beam aperture, an objective lens for focusing the charged particle beam on a sample, a detector that detects secondary charged particles emitted by irradiating the sample with the charged particle beam, a computer that forms a charged particle beam image based on the secondary charged particles detected by the detector, in which the position of the charged particle beam aperture is set so that the charged particle beam image does not move and changes concentrically in synchronization with the AC voltage, in a state where an AC voltage is applied to the charged particle beam aperture by the charged particle beam aperture power supply.

A charged-particle beam (CPB) is aligned to a primary axis of a CPB microscope by determining a first beam deflection drive to a beam deflector for directing the CPB passing a reference location displaced from the primary axis. The beam deflector is provided with a second beam deflection drive during the working mode of the CPB microscope to propagate the beam along the primary axis. The second beam deflection drive is determined based on the first beam deflection drive.

A charged particle beam device includes a charged particle source which emits a charged particle beam radiated on a sample; a condenser lens system which has at least one condenser lens focusing the charged particle beam at a predetermined demagnification; a deflector which is positioned between a condenser lens of a most downstream side and a charged particle source in the condenser lens system, and moves a virtual position of the charged particle source; and a control unit which controls the deflector and the condenser lens system. The control unit controls the deflector to move the virtual position of the charged particle source to a position of suppressing a deviation, which is caused by a change of the demagnification of the condenser lens system, of a center trajectory of the charged particle beam downstream of the condenser lens system.

A multi-beam apparatus for observing a sample with high resolution and high throughput and in flexibly varying observing conditions is proposed. The apparatus uses a movable collimating lens to flexibly vary the currents of the plural probe spots without influencing the intervals thereof, a new source-conversion unit to form the plural images of the single electron source and compensate off-axis aberrations of the plural probe spots with respect to observing conditions, and a pre-beamlet-forming means to reduce the strong Coulomb effect due to the primary-electron beam.

Intraoral three-dimensional (3D) tomosynthesis imaging systems, methods, and non-transitory computer readable media are used to generate one or more two-dimensional (2D) x-ray projection images and to reconstruct, using a computing platform, the one or more 2D x-ray projection images into one or more 3D images of an object, such as teeth of a patient, which can then be displayed on a monitor in order to enhance diagnostic accuracy of dental disease. The intraoral 3D tomosynthesis imaging system can include a wall-mountable control unit connected to one end of an articulating arm, the other end of which is connected to an x-ray source, which is configured to generate x-ray radiation that is acquired by an x-ray detector held at a desired position by an x-ray detector holder that is removably coupled to a collimator at an emission region of the x-ray source.