.. auto-generated by script ../../../../utils/nxdl2rst.py from the NXDL source NXattenuator.nxdl.xml

.. index::
    ! NXattenuator (base class)
    ! attenuator (base class)
    see: attenuator (base class); NXattenuator

.. _NXattenuator:

============
NXattenuator
============

**Status**:

  base class, extends :ref:`NXobject`

**Description**:

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

  If uncertain whether to use :ref:`NXfilter` (band-pass filter)
  or :ref:`NXattenuator` (reduces beam intensity), then choose 
  :ref:`NXattenuator`.

**Symbols**:

  No symbol table

**Groups cited**:
  none

**Structure**:

  .. _/NXattenuator@default-attribute:

  .. index:: default (file attribute)

  **@default**: (optional) :ref:`NX_CHAR <NX_CHAR>`

    .. index:: plotting

    Declares which child group contains a path leading 
    to a :ref:`NXdata` group.

    It is recommended (as of NIAC2014) to use this attribute
    to help define the path to the default dataset to be plotted.
    See https://www.nexusformat.org/2014_How_to_find_default_data.html
    for a summary of the discussion.

  .. _/NXattenuator/distance-field:

  .. index:: distance (field)

  **distance**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_LENGTH <NX_LENGTH>`}

    Distance from sample

  .. _/NXattenuator/type-field:

  .. index:: type (field)

  **type**: (optional) :ref:`NX_CHAR <NX_CHAR>`

    Type or composition of attenuator, e.g. polythene

  .. _/NXattenuator/thickness-field:

  .. index:: thickness (field)

  **thickness**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_LENGTH <NX_LENGTH>`}

    Thickness of attenuator along beam direction

  .. _/NXattenuator/scattering_cross_section-field:

  .. index:: scattering_cross_section (field)

  **scattering_cross_section**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_CROSS_SECTION <NX_CROSS_SECTION>`}

    Scattering cross section (coherent+incoherent)

  .. _/NXattenuator/absorption_cross_section-field:

  .. index:: absorption_cross_section (field)

  **absorption_cross_section**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_CROSS_SECTION <NX_CROSS_SECTION>`}

    Absorption cross section

  .. _/NXattenuator/attenuator_transmission-field:

  .. index:: attenuator_transmission (field)

  **attenuator_transmission**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_DIMENSIONLESS <NX_DIMENSIONLESS>`}

    The nominal amount of the beam that gets through
    (transmitted intensity)/(incident intensity)

  .. _/NXattenuator/status-field:

  .. index:: status (field)

  **status**: (optional) :ref:`NX_CHAR <NX_CHAR>`

    In or out or moving of the beam

    Any of these values: ``in`` | ``out`` | ``moving``

    .. _/NXattenuator/status@time-attribute:

    .. index:: time (field attribute)

    **@time**: (optional) :ref:`NX_DATE_TIME <NX_DATE_TIME>`

      time stamp for this observation


Hypertext Anchors
-----------------

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


================================================================================================== ==================================================================================================
documentation (reST source) anchor                                                                 web page (HTML) anchor                                                                            
================================================================================================== ==================================================================================================
:ref:`/NXattenuator/absorption_cross_section-field </NXattenuator/absorption_cross_section-field>` :ref:`#nxattenuator-absorption-cross-section-field </NXattenuator/absorption_cross_section-field>`
:ref:`/NXattenuator/attenuator_transmission-field </NXattenuator/attenuator_transmission-field>`   :ref:`#nxattenuator-attenuator-transmission-field </NXattenuator/attenuator_transmission-field>`  
:ref:`/NXattenuator/distance-field </NXattenuator/distance-field>`                                 :ref:`#nxattenuator-distance-field </NXattenuator/distance-field>`                                
:ref:`/NXattenuator/scattering_cross_section-field </NXattenuator/scattering_cross_section-field>` :ref:`#nxattenuator-scattering-cross-section-field </NXattenuator/scattering_cross_section-field>`
:ref:`/NXattenuator/status-field </NXattenuator/status-field>`                                     :ref:`#nxattenuator-status-field </NXattenuator/status-field>`                                    
:ref:`/NXattenuator/status@time-attribute </NXattenuator/status@time-attribute>`                   :ref:`#nxattenuator-status-time-attribute </NXattenuator/status@time-attribute>`                  
:ref:`/NXattenuator/thickness-field </NXattenuator/thickness-field>`                               :ref:`#nxattenuator-thickness-field </NXattenuator/thickness-field>`                              
:ref:`/NXattenuator/type-field </NXattenuator/type-field>`                                         :ref:`#nxattenuator-type-field </NXattenuator/type-field>`                                        
:ref:`/NXattenuator@default-attribute </NXattenuator@default-attribute>`                           :ref:`#nxattenuator-default-attribute </NXattenuator@default-attribute>`                          
================================================================================================== ==================================================================================================


**NXDL Source**:
  https://github.com/nexusformat/definitions/blob/main/base_classes/NXattenuator.nxdl.xml