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.
- 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
Draft 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.
- NXcollectioncolumn
Draft subclass of NXelectronanalyser to describe the electron collection column of a photoelectron analyser.
- NXcollimator
A beamline collimator.
- NXcorrector_cs
Draft of a base class for a device in a (transmission) electron microscope which corrects for spherical aberrations. The device consists of multiple NXlens_em instances and other components.
- NXcrystal
A crystal monochromator or analyzer.
- NXcylindrical_geometry
Geometry description for cylindrical shapes.
- NXdata
NXdata describes the plottable data and related dimension scales.
- NXdeflector
Draft class definition for electro-static deflectors as they are used e.g. in an electron analyser.
- NXdetector
A detector, detector bank, or multidetector.
- 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
Draft subclass of NXprocess to describe post-processing distortion correction.
- NXelectronanalyser
Draft subclass of NXinstrument to describe a photoelectron analyser.
- NXenergydispersion
Draft subclass of NXelectronanalyser to describe the energy dispersion section of a photoelectron analyser.
- 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
- NXfermi_chopper
A Fermi chopper, possibly with curved slits.
- NXfib
Draft of a base class for describing focused-ion beam capabilities of an instrument. The class is designed to be used as an additional component of e.g. an electron microscope to describe sample/specimen preparation and the collecting of data and metadata for (scanning) electron microscope/focused-ion beam, (S)EM/FIB instruments.
- 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.
- NXinsertion_device
An insertion device, as used in a synchrotron light source.
- NXinstrument
Collection of the components of the instrument or beamline.
- NXion
Atomic architecture of a (molecular) ion (fragment) which can be used for example to label charged molecule ions identified from mass-to-charge histogram data as appearing as signal in e.g. time-resolved mass spectrometry techniques like atom probe or secondary ion mass spectrometry.
- NXlens
Draft class definition for electro-static lenses as they are used e.g. in an electron analyser.
- NXlens_apm
Draft class definition for a component of an atom probe instrument which details an eventually available reflectron device whose purpose is to deflect the flight paths of the ions to realize what is effectively an energy compensation.
- NXlens_em
Draft base class definition for electro-magnetic lenses as they are used e.g. in an electron microscope or reflectron device in a local electrode atom probe microscope.
- NXlog
Information recorded as a function of time.
- NXmanipulator
Draft extension of NXpositioner to include fields to describe the use of manipulators in photoemission experiments.
- 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
- 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
- NXpeak
Proposal for storing mathematical models of peaks, their functional form or at least their measured support.
- 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.
- NXpulser_apm
Draft for a class which can be used for representing a coarse-grained description of all those components of an atom probe microscope which realize the pulsing capabilities, whether it be for the laser or the high-voltage pulser, which trigger the removal of ions (atom probe tomography) or the excitation of gas ions (field-ion microscopy).
- NXreflections
Reflection data from diffraction experiments
- NXregistration
Draft extension of NXobject to include fields to describe image registration procedures.
- 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.
- NXscanbox_em
Description of the scan box which is instructed by the microscope control software to direct the probe to controlled locations according to a scan scheme and plan.
- 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
The neutron or x-ray storage ring/facility.
- NXspindispersion
Draft subclass of NXelectronanalyser to describe the spin filters in photoemission experiments.
- NXstage_lab
Candidate class for a component or a set of components which is coarse-grained into one logical unit. The role of the stage in an experiment is to hold/align/orient the sample/specimen and eventually offer a controlled environment and further devices to apply stimuli. Having an own candidate class is justified as contemporary specimen/sample stages are such multi-purpose/-functional tools with multiple actuators, sensors, components, and thus also the need to store the various (meta)data that are generated with manipulating the sample. Modern stages realize a hierarchy of components for achieving these tasks. For example the specimen might be mounted on a multi-axial tilt rotation holders which itself is fixed in the support unit that connects to the microscope. In other examples, taken from atom probe microscopy for instance, researchers may work with wire samples which are clipped into a larger fixing unit for convenience. This unit is known in atom probe jargon as a stub. Stubs in turn are positioned on pucks. Pucks are then loaded onto carousels. This NXstage class reflects two layers of this hierarchy. The stage is the root of the hierarchy. A stage carries the holder. In the case that it is not practical to distinguish these two layers, the holder should be given preference. Applied to examples, a nanoparticle is attached on a copper grid. The copper grid is the holder. The grid itself is fixed to the stage. An atom probe specimen is fixed in a stub, in this case the stub can be considered as the holder, while the cryostat temperature control unit reads more as the stage. A microtip on a microtip array is an example of a three-layer hierarchy commonly employed for efficient sequential processing of atom probe experiments. For a single experiment though only one microtip of the array at a time can be measured. Therefore, the microtip is the specimen, the array the holder and the remaining mounting unit that is attached to the cryo-controller the stage. To cover for an as flexible design of these complex lab-like modern stages users should nest NXstage_lab objects for reflect the differences between e.g. a holder and a stage.
- 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.
