application definition, extends NXobject


Monochromatic Neutron and X-Ray Powder diffractometer

Instrument definition for a powder diffractometer at a monochromatic neutron or X-ray beam. This is both suited for a powder diffractometer with a single detector or a powder diffractometer with a position sensitive detector.


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

i: i is the number of wavelengths

nDet: Number of detectors

Groups cited:

NXcrystal, NXdata, NXdetector, NXentry, NXinstrument, NXmonitor, NXsample, NXsource


entry: (required) NXentry

title: (required) NX_CHAR

start_time: (required) NX_DATE_TIME

definition: (required) NX_CHAR

Official NeXus NXDL schema to which this file conforms

Obligatory value: NXmonopd

INSTRUMENT: (required) NXinstrument

SOURCE: (required) NXsource

type: (required) NX_CHAR

name: (required) NX_CHAR

probe: (required) NX_CHAR

Any of these values: neutron | x-ray | electron

CRYSTAL: (required) NXcrystal

wavelength: (required) NX_FLOAT (Rank: 1, Dimensions: [i]) {units=NX_WAVELENGTH}

Optimum diffracted wavelength

DETECTOR: (required) NXdetector

polar_angle: (required) NX_FLOAT (Rank: 1, Dimensions: [nDet])

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

detector signal (usually counts) are already corrected for detector efficiency

SAMPLE: (required) NXsample

name: (required) NX_CHAR

Descriptive name of sample

rotation_angle: (required) NX_FLOAT {units=NX_ANGLE}

Optional rotation angle for the case when the powder diagram has been obtained through an omega-2theta scan like from a traditional single detector powder diffractometer

MONITOR: (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

integral: (required) NX_FLOAT {units=NX_ANY}

Total integral monitor counts

DATA: (required) NXdata

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

Link to polar angle in /NXentry/NXinstrument/NXdetector

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

Link to data in /NXentry/NXinstrument/NXdetector

Hypertext Anchors

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

NXDL Source: