NXlauetof

Status:

application definition, extends NXobject

Description:

This is the application definition for a TOF laue diffractometer

Symbols:

The symbol(s) listed here will be used below to coordinate datasets with the same shape.

nXPixels: Number of X pixels

nYPixels: Number of Y pixels

nTOF: Time of flight

Groups cited:

NXdata, NXdetector, NXentry, NXinstrument, NXmonitor, NXsample

Structure:

entry: (required) NXentry

definition: (required) NX_CHAR

Official NeXus NXDL schema to which this file conforms

Obligatory value: NXlauetof

instrument: (required) NXinstrument

detector: (required) NXdetector

This assumes a planar 2D detector. All angles and distances refer to the center of the detector.

polar_angle: (required) NX_FLOAT {units=NX_ANGLE}

The polar_angle (two theta) where the detector is placed.

azimuthal_angle: (required) NX_FLOAT {units=NX_ANGLE}

The azimuthal angle where the detector is placed.

data: (required) NX_INT (Rank: 3, Dimensions: [nXPixels, nYPixels, nTOF])

@signal: (required) NX_POSINT

Obligatory value: 1

x_pixel_size: (required) NX_FLOAT {units=NX_LENGTH}

y_pixel_size: (required) NX_FLOAT {units=NX_LENGTH}

distance: (required) NX_FLOAT {units=NX_LENGTH}

time_of_flight: (required) NX_FLOAT (Rank: 1, Dimensions: [nTOF]) {units=NX_TIME_OF_FLIGHT}

sample: (required) NXsample

name: (required) NX_CHAR

Descriptive name of sample

orientation_matrix: (required) NX_FLOAT (Rank: 2, Dimensions: [3, 3])

The orientation matrix according to Busing and Levy conventions. This is not strictly necessary as the UB can always be derived from the data. But let us bow to common usage which includes thie UB nearly always.

unit_cell: (required) NX_FLOAT (Rank: 1, Dimensions: [6])

The unit cell, a, b, c, alpha, beta, gamma. Again, not strictly necessary, but normally written.

control: (required) NXmonitor

mode: (required) NX_CHAR

Count to a preset value based on either clock time (timer) or received monitor counts

(monitor).

Any of these values: monitor | timer

preset: (required) NX_FLOAT

preset value for time or monitor

data: (required) NX_INT (Rank: 1, Dimensions: [nTOF])

use these attributes primary=1 signal=1

time_of_flight: (required) NX_FLOAT (Rank: 1, Dimensions: [nTOF]) {units=NX_TIME_OF_FLIGHT}

name: (required) NXdata

data: link (suggested target: /NXentry/NXinstrument/NXdetector/data)

time_of_flight: link (suggested target: /NXentry/NXinstrument/NXdetector/time_of_flight)

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/applications/NXlauetof.nxdl.xml