.. do NOT edit this file
   automatically generated by dev_tools.docs.nxdl_index


.. index::
     ! see: class definitions; base class
     ! base class

.. _base.class.definitions:

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.
    

:ref:`NXaperture`
    A beamline aperture. This group is deprecated, use NXslit instead.

:ref:`NXattenuator`
    A device that reduces the intensity of a beam by attenuation.

:ref:`NXbeam`
    Properties of the neutron or X-ray beam at a given location. 

:ref:`NXbeam_stop`
    A device that blocks the beam completely, usually to protect a detector. 

:ref:`NXbending_magnet`
    A bending magnet

:ref:`NXcapillary`
    A capillary lens to focus the X-ray beam.

:ref:`NXcite`
    A literature reference

:ref:`NXcollection`
    An unvalidated set of terms, such as the description of a beam line.

:ref:`NXcollimator`
    A beamline collimator.

:ref:`NXcrystal`
    A crystal monochromator or analyzer. 

:ref:`NXcylindrical_geometry`
    Geometry description for cylindrical shapes.

:ref:`NXdata`
    :ref:`NXdata` describes the plottable data and related dimension scales. 

:ref:`NXdetector`
    A detector, detector bank, or multidetector.

:ref:`NXdetector_group`
    Logical grouping of detectors. When used, describes a group of detectors.

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

:ref:`NXdisk_chopper`
    A device blocking the beam in a temporal periodic pattern.

:ref:`NXentry`
    (**required**) :ref:`NXentry` describes the measurement.

:ref:`NXenvironment`
    Parameters for controlling external conditions

:ref:`NXevent_data`
    NXevent_data is a special group for storing data from neutron

:ref:`NXfermi_chopper`
    A Fermi chopper, possibly with curved slits.

:ref:`NXfilter`
    For band pass beam filters.

:ref:`NXflipper`
    A spin flipper.

:ref:`NXfresnel_zone_plate`
    A fresnel zone plate

:ref:`NXgeometry`
    legacy class - recommend to use :ref:`NXtransformations` now

:ref:`NXgrating`
    A diffraction grating, as could be used in a soft X-ray monochromator

:ref:`NXguide`
    A neutron optical element to direct the path of the beam.

:ref:`NXinsertion_device`
    An insertion device, as used in a synchrotron light source.

:ref:`NXinstrument`
    Collection of the components of the instrument or beamline.

:ref:`NXlog`
    Information recorded as a function of time.

:ref:`NXmirror`
    A beamline mirror or supermirror.

:ref:`NXmoderator`
    A neutron moderator

:ref:`NXmonitor`
    A monitor of incident beam data. 

:ref:`NXmonochromator`
    A  wavelength defining device.

:ref:`NXnote`
    Any additional freeform information not covered by the other base classes.

:ref:`NXobject`
    This is the base object of NeXus

:ref:`NXoff_geometry`
    Geometry (shape) description.

:ref:`NXorientation`
    legacy class - recommend to use :ref:`NXtransformations` now

:ref:`NXparameters`
    Container for parameters, usually used in processing or analysis.

:ref:`NXpdb`
    A NeXus transliteration of a PDB file, to be validated only as a PDB

:ref:`NXpinhole`
    A simple pinhole.

:ref:`NXpolarizer`
    A spin polarizer.

:ref:`NXpositioner`
    A generic positioner such as a motor or piezo-electric transducer.

:ref:`NXprocess`
    Document an event of data processing, reconstruction, or analysis for this data.

:ref:`NXreflections`
    Reflection data from diffraction experiments

:ref:`NXroot`
    Definition of the root NeXus group.

:ref:`NXsample`
    Any information on the sample. 

:ref:`NXsample_component`
    One group like this per component can be recorded For a sample consisting of multiple components.

:ref:`NXsensor`
    A sensor used to monitor an external condition 

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

:ref:`NXslit`
    A simple slit.

:ref:`NXsource`
    The neutron or x-ray storage ring/facility.

:ref:`NXsubentry`
    Group of multiple application definitions for "multi-modal" (e.g. SAXS/WAXS) measurements.

:ref:`NXtransformations`
    Collection of axis-based translations and rotations to describe a geometry.

:ref:`NXtranslation`
    legacy class - (used by :ref:`NXgeometry`) - general spatial location of a component.

:ref:`NXuser`
    Contact information for a user.  

:ref:`NXvelocity_selector`
    A neutron velocity selector

:ref:`NXxraylens`
    An X-ray lens, typically at a synchrotron X-ray beam line.

.. toctree::
    :hidden:

    NXaperture
    NXattenuator
    NXbeam
    NXbeam_stop
    NXbending_magnet
    NXcapillary
    NXcite
    NXcollection
    NXcollimator
    NXcrystal
    NXcylindrical_geometry
    NXdata
    NXdetector
    NXdetector_group
    NXdetector_module
    NXdisk_chopper
    NXentry
    NXenvironment
    NXevent_data
    NXfermi_chopper
    NXfilter
    NXflipper
    NXfresnel_zone_plate
    NXgeometry
    NXgrating
    NXguide
    NXinsertion_device
    NXinstrument
    NXlog
    NXmirror
    NXmoderator
    NXmonitor
    NXmonochromator
    NXnote
    NXobject
    NXoff_geometry
    NXorientation
    NXparameters
    NXpdb
    NXpinhole
    NXpolarizer
    NXpositioner
    NXprocess
    NXreflections
    NXroot
    NXsample
    NXsample_component
    NXsensor
    NXshape
    NXslit
    NXsource
    NXsubentry
    NXtransformations
    NXtranslation
    NXuser
    NXvelocity_selector
    NXxraylens