2.3.3.1. Base Class Definitions

A description of each NeXus base class definition is given. NeXus base class definitions define the set of terms that might be used in an instance of that class. Consider the base classes as a set of components that are used to construct a data file.

NXactivity

A planned or unplanned action that has a temporal extension and for some time depends on some entity.

NXactuator

An actuator used to control an external condition.

NXaperture

A beamline aperture.

NXattenuator

A device that reduces the intensity of a beam by attenuation.

NXbeam

Properties of the neutron or X-ray beam at a given location.

NXbeam_stop

A device that blocks the beam completely, usually to protect a detector.

NXbending_magnet

A bending magnet

NXcalibration

Subclass of NXprocess to describe post-processing calibrations.

NXcapillary

A capillary lens to focus the X-ray beam.

NXcite

A literature reference

NXcollection

An unvalidated set of terms, such as the description of a beam line.

NXcollimator

A beamline collimator.

NXcomponent

Base class for components of an instrument - real ones or simulated ones.

NXcrystal

A crystal monochromator or analyzer.

NXcylindrical_geometry

Geometry description for cylindrical shapes.

NXdata

The NXdata class is designed to encapsulate all the information required for a set of data to be plotted.

NXdetector

A detector, detector bank, or multidetector.

NXdetector_channel

Description and metadata for a single channel from a multi-channel detector.

NXdetector_group

Logical grouping of detectors. When used, describes a group of detectors.

NXdetector_module

Geometry and logical description of a detector module. When used, child group to NXdetector.

NXdisk_chopper

A device blocking the beam in a temporal periodic pattern.

NXdistortion

Subclass of NXprocess to describe post-processing distortion correction.

NXelectron_detector

A subclass of NXdetector for detectors that detect electrons.

NXentry

(required) NXentry describes the measurement.

NXenvironment

Parameters for controlling external conditions

NXevent_data

NXevent_data is a special group for storing data from neutron

NXfabrication

Details about a component as it is defined by its manufacturer.

NXfermi_chopper

A Fermi chopper, possibly with curved slits.

NXfilter

For band pass beam filters.

NXflipper

A spin flipper.

NXfresnel_zone_plate

A fresnel zone plate

NXgeometry

legacy class - recommend to use NXtransformations now

NXgrating

A diffraction grating, as could be used in a soft X-ray monochromator

NXguide

A neutron optical element to direct the path of the beam.

NXhistory

A set of activities that occurred to a physical entity prior/during experiment.

NXinsertion_device

An insertion device, as used in a synchrotron light source.

NXinstrument

Collection of the components of the instrument or beamline.

NXlens_em

Base class for an electro-magnetic lens or a compound lens.

NXlog

Information recorded as a function of time.

NXmirror

A beamline mirror or supermirror.

NXmoderator

A neutron moderator

NXmonitor

A monitor of incident beam data.

NXmonochromator

A wavelength defining device.

NXnote

Any additional freeform information not covered by the other base classes.

NXobject

This is the base object of NeXus. The groups and fields contained

NXoff_geometry

Geometry (shape) description.

NXorientation

legacy class - recommend to use NXtransformations now

NXparameters

Container for parameters, usually used in processing or analysis.

NXpdb

A NeXus transliteration of a PDB file, to be validated only as a PDB

NXpid_controller

A description of a feedback system in terms of the settings of a proportional-integral-derivative (PID) controller.

NXpinhole

A simple pinhole.

NXpolarizer

A spin polarizer.

NXpositioner

A generic positioner such as a motor or piezo-electric transducer.

NXprocess

Document an event of data processing, reconstruction, or analysis for this data.

NXreflections

Reflection data from diffraction experiments

NXregistration

Describes image registration procedures.

NXresolution

Describes the resolution of a physical quantity.

NXroot

Definition of the root NeXus group.

NXsample

Any information on the sample.

NXsample_component

One group like this per component can be recorded for a sample consisting of multiple components.

NXsensor

A sensor used to monitor an external condition

NXshape

legacy class - (used by NXgeometry) - the shape and size of a component.

NXslit

A simple slit.

NXsource

Radiation source emitting a beam.

NXsubentry

Group of multiple application definitions for “multi-modal” (e.g. SAXS/WAXS) measurements.

NXtransformations

Collection of axis-based translations and rotations to describe a geometry.

NXtranslation

legacy class - (used by NXgeometry) - general spatial location of a component.

NXuser

Contact information for a user.

NXvelocity_selector

A neutron velocity selector

NXxraylens

An X-ray lens, typically at a synchrotron X-ray beam line.