This charged particle gun has a bolt to which a charged particle source is attached, a nut that is screwed together with the bolt and thereby holds the charged particle source, and a nut seat surface in contact with the nut. The nut includes an inclination adjustment section whereby it is possible to adjust the angle of inclination of the charged particle source with respect to the nut seat surface, and a lock section that inhibits the nut and the bolt from becoming loose when screwed together. The inner surface of the nut has a screw thread section and a non-screw thread section with a larger inner diameter than the screw thread section. The inclination adjustment section has: a first slit formed so as to pass through an area from one part of the outer surface of the nut to one part of the non-screw thread section; an inclination adjustment screw; a first part positioned between the first slit and a second surface; a second part positioned between the first slit and a first surface; and a first screw hole that is screwed together with the inclination adjustment screw and formed so as to pass through an area from the first surface to the first slit in the second part.

Crystallographic information of crystalline sample can be determined from one or more three-dimensional diffraction pattern datasets generated based on diffraction patterns collected from multiple crystals. The crystals for diffraction pattern acquisition may be selected based on a sample image. At a location of each selected crystal, multiple diffraction patterns of the crystal are acquired at different angles of incidence by tilting the electron beam, wherein the sample is not rotated while the electron beam is directed at the selected crystal.

A method of, and a detector for, performing energy sensitive imaging of ionizing radiation are provided, including acquiring a first frame having a plurality of pixels, each pixel of the plurality having an energy of detection and a location; grouping, into a cluster, pixels of the plurality having an energy of detection above a predetermined threshold and a location along with at least one other pixel also having an energy of detection above the predetermined threshold and being within a predetermined distance of the location; summing the energy of detection of all pixels within the grouped cluster to determine a cluster energy; determining a location of the cluster based on a distribution and an intensity of the summed energy of detection; and generating an image of the cluster based on the determined cluster energy and the determined location of the cluster.

Crystallographic information of crystalline sample can be determined from one or more three-dimensional diffraction pattern datasets generated based on diffraction patterns collected from multiple crystals. The crystals for diffraction pattern acquisition may be selected based on a sample image. At a location of each selected crystal, multiple diffraction patterns of the crystal are acquired at different angles of incidence by tilting the electron beam, wherein the sample is not rotated while the electron beam is directed at the selected crystal.

A method of acquiring a dark-field image for a scanning transmission electron microscope is provided. The scanning transmission electron microscope includes a dark-field detector having an annular detection region which is capable of detecting electrons scattered at a specimen in a predetermined angular range, an objective lens, and an imaging lens group disposed at a stage following the objective lens. The method includes reducing an influence of a geometrical aberration on the electrons scattered in the predetermined angular range by shifting a focus of the imaging lens group from a diffraction plane of the objective lens.

A detector for Kikuchi diffraction comprising a detector body and a detector head mountable to each other. The detector body comprises a body part which is enclosing a photodetector configured for detecting incident radiation and further comprises a vacuum window arranged upstream the photodetector with respect to a propagation direction of the incident radiation, a first body mounting portion configured to be mounted to a SEM chamber port and a second body mounting portion. The detector head comprises a scintillation screen and a head mounting portion configured to be mounted to the second body mounting portion.

A method of indexing an electron diffraction pattern comprises obtaining a number of experimental electron diffraction patterns at a low resolution from a sample of material using a detector. A master simulation dataset is loaded into the primary memory of a computer system for each phase of the sample material. A simulated template is generated at the low resolution in the primary memory of the computer by using the master simulation dataset from the primary memory wherein the simulated template represents a simulated electron diffraction pattern for a nominal crystallographic orientation. The simulated template is compared with the experimental electron diffraction pattern so as to generate a corresponding similarity measure which is stored. The process is repeated for all crystallographic orientations using crystallographic orientation intervals, and for each phase and each location on the sample. The similarity measures stored in step f are then analysed so as to select at least one resultant indexed phase and orientation for each location. A system configured to perform the method is also provided.

Various methods and systems are provided for acquiring electron backscatter diffraction patterns. In one example, a first scan is performed by directing a charged particle beam towards multiple impact points within a ROI and detecting particles scattered from the multiple impact points. A signal quality of each impact point of the multiple impact points is calculated based on the detected particles. A signal quality of the ROI is calculated based on the signal quality of each impact point. Responsive to the signal quality of the ROI lower than a threshold signal quality, a second scan of the ROI is performed. A structural image of the sample may be formed based on detected particles from both the first scan and the second scan.

A method of acquiring a dark-field image for a scanning transmission electron microscope is provided. The scanning transmission electron microscope includes a dark-field detector having an annular detection region which is capable of detecting electrons scattered at a specimen in a predetermined angular range, an objective lens, and an imaging lens group disposed at a stage following the objective lens. The method includes reducing an influence of a geometrical aberration on the electrons scattered in the predetermined angular range by shifting a focus of the imaging lens group from a diffraction plane of the objective lens.

A detector for Kikuchi diffraction comprising a detector body and a detector head mountable to each other. The detector body comprises a body part which is enclosing a photodetector configured for detecting incident radiation and further comprises a vacuum window arranged upstream the photodetector with respect to a propagation direction of the incident radiation, a first body mounting portion configured to be mounted to a SEM chamber port and a second body mounting portion. The detector head comprises a scintillation screen and a head mounting portion configured to be mounted to the second body mounting portion.