2.3.3.3.122. NXevent_data_em

Status:

base class, extends NXobject

Description:

Symbols:

No symbol table

Groups cited:

NXchamber, NXdetector, NXebeam_column, NXibeam_column, NXimage_set, NXinstrument, NXinteraction_vol_em, NXoptical_system_em, NXpump, NXspectrum_set, NXstage_lab, NXuser

Structure:

start_time: (optional) NX_DATE_TIME

ISO 8601 time code with local time zone offset to UTC information included ...

ISO 8601 time code with local time zone offset to UTC information included when the snapshot time interval started. If the user wishes to specify an interval of time that the snapshot should represent during which the instrument was stable and configured using specific settings and calibrations, the start_time is the start (left bound of the time interval) while the end_time specifies the end (right bound) of the time interval.

end_time: (optional) NX_DATE_TIME

ISO 8601 time code with local time zone offset to UTC information included ...

ISO 8601 time code with local time zone offset to UTC information included when the snapshot time interval ended.

event_identifier: (optional) NX_INT {units=NX_UNITLESS}

Identifier of a specific state and setting of the microscope.

event_type: (optional) NX_CHAR

Which specific event/measurement type. Examples are: ...

Which specific event/measurement type. Examples are:

  • In-lens/backscattered electron, usually has quadrants

  • Secondary_electron, image, topography, fractography, overview images

  • Backscattered_electron, image, Z or channeling contrast (ECCI)

  • Bright_field, image, TEM

  • Dark_field, image, crystal defects

  • Annular dark field, image (medium- or high-angle), TEM

  • Diffraction, image, TEM, or a comparable technique in the SEM

  • Kikuchi, image, SEM EBSD and TEM diffraction

  • X-ray spectra (point, line, surface, volume), composition EDS/EDX(S)

  • Electron energy loss spectra for points, lines, surfaces, TEM

  • Auger, spectrum, (low Z contrast element composition)

  • Cathodoluminescence (optical spectra)

  • Ronchigram, image, alignment utility specifically in TEM

  • Chamber, e.g. TV camera inside the chamber, education purposes.

This field may also be used for storing additional information about the event. For which there is at the moment no other place.

In the long run such free-text field description should be avoided as they are difficult to machine-interpret. Instead, reference should be given to refactoring these descriptions into structured metadata. The reason why in this base class the field event_type is nonetheless kept is to offer a place whereby practically users may enter data for follow-up modifications to support arriving at an improved NXevent_data_em base class.

IMAGE_SET: (optional) NXimage_set

SPECTRUM_SET: (optional) NXspectrum_set

em_lab: (optional) NXinstrument

(Meta)data of the dynamics and changes of the microscope during the event.

CHAMBER: (optional) NXchamber

EBEAM_COLUMN: (optional) NXebeam_column

IBEAM_COLUMN: (optional) NXibeam_column

OPTICAL_SYSTEM_EM: (optional) NXoptical_system_em

DETECTOR: (optional) NXdetector

PUMP: (optional) NXpump

STAGE_LAB: (optional) NXstage_lab

USER: (optional) NXuser

INTERACTION_VOL_EM: (optional) NXinteraction_vol_em

Hypertext Anchors

List of hypertext anchors for all groups, fields, attributes, and links defined in this class.

NXDL Source:

https://github.com/FAIRmat-NFDI/nexus_definitions/tree/fairmat/contributed_definitions/NXevent_data_em.nxdl.xml