NXimage_set_em_se

Status:

base class, extends NXobject

Description:

Container for reporting a set of secondary electron images.

Secondary electron images are one of the most important signal especially for scanning electron microscopy in materials science and engineering, for analyses of surface topography, getting an overview of the analysis region, or fractography.

Symbols:

n_images: Number of images.

n_y: Number of pixels along the slow scan direction (often y).

n_x: Number of pixels along the fast scan direction (often x).

Groups cited:

NXdata, NXoptical_system_em, NXprocess

Structure:

roi: (optional) NX_NUMBER (Rank: 2, Dimensions: [n_images, 4]) {units=NX_LENGTH}

Physical dimensions of the region-of-interest on the specimen surface which the image covers. The first and second number are the coordinates for the minimum edge, the third and fourth number are the coordinates for the maximum edge of the rectangular ROI.

dwell_time: (optional) NX_FLOAT {units=NX_TIME}

number_of_frames_averaged: (optional) NX_UINT (Rank: 1, Dimensions: [n_images]) {units=NX_UNITLESS}

How many frames were averaged to obtain the image.

bias_voltage: (optional) NX_FLOAT

Bias voltage applied to the e.g. Faraday cage in front of the SE detector to attract or repell secondary electrons below a specific kinetic energy.

DATA: (optional) NXdata

Collected secondary electron images (eventually as an image stack).

intensity: (optional) NX_NUMBER (Rank: 3, Dimensions: [n_p, n_y, n_x]) {units=NX_UNITLESS}

@long_name: (optional) NX_CHAR

Secondary electron image intensity

image_id: (optional) NX_NUMBER (Rank: 1, Dimensions: [n_p]) {units=NX_UNITLESS}

@long_name: (optional) NX_CHAR

Image identifier

ypos: (optional) NX_NUMBER (Rank: 1, Dimensions: [n_y]) {units=NX_LENGTH}

@long_name: (optional) NX_CHAR

Label for the y axis

xpos: (optional) NX_NUMBER (Rank: 1, Dimensions: [n_x]) {units=NX_LENGTH}

@long_name: (optional) NX_CHAR

Label for the x axis

OPTICAL_SYSTEM_EM: (optional) NXoptical_system_em

Container to store relevant settings affecting beam path, magnification, and working_distance

scan_rotation: (optional) NXprocess

Scan rotation is an option offer by most control software.

tilt_correction: (optional) NXprocess

Tilt correction is an option offered by most control software of SEMs to apply an on-the-fly processing of the image to correct for the excursion of objects when characterized with SE images on samples whose surface normal is tilted about an axis perpendicular to the optical axis.

active: (optional) NX_BOOLEAN

Was the option switched active or not.

dynamic_focus: (optional) NXprocess

Dynamic focus is an option offered by most control software of SEMs to keep the image also focused when probing locations on the specimens beyond those for which the lens system was calibrated.

active: (optional) NX_BOOLEAN

Was the option switched active or not.

Hypertext Anchors

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

NXDL Source:

https://github.com/FAIRmat-Experimental/nexus_definitions/tree/fairmat/contributed_definitions/NXimage_set_em_se.nxdl.xml