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

.. index::
    ! NXmoderator (base class)
    ! moderator (base class)
    see: moderator (base class); NXmoderator

.. _NXmoderator:

===========
NXmoderator
===========

**Status**:

  base class, extends :ref:`NXobject`, version 1.0

**Description**:

  A neutron moderator

**Symbols**:

  No symbol table

**Groups cited**:
  :ref:`NXdata`, :ref:`NXgeometry`, :ref:`NXlog`

.. index:: NXgeometry (base class); used in base class, NXlog (base class); used in base class, NXdata (base class); used in base class

**Structure**:

  .. index:: distance (field)

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

    Effective distance as seen by measuring radiation

  .. index:: type (field)

  **type**: :ref:`NX_CHAR <NX_CHAR>`


    Any of these values:

      * ``H20``

      * ``D20``

      * ``Liquid H2``

      * ``Liquid CH4``

      * ``Liquid D2``

      * ``Solid D2``

      * ``C``

      * ``Solid CH4``

      * ``Solid H2``


  .. index:: poison depth (field)

  **poison_depth**: :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_LENGTH <NX_LENGTH>`}


  .. index:: coupled (field)

  **coupled**: :ref:`NX_BOOLEAN <NX_BOOLEAN>`

    whether the moderator is coupled

  .. index:: coupling material (field)

  **coupling_material**: :ref:`NX_CHAR <NX_CHAR>`

    The material used for coupling. Usually Cd.

  .. index:: poison material (field)

  **poison_material**: :ref:`NX_CHAR <NX_CHAR>`


    Any of these values: ``Gd`` | ``Cd``

  .. index:: temperature (field)

  **temperature**: :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_TEMPERATURE <NX_TEMPERATURE>`}

    average/nominal moderator temperature

  **(geometry)**: :ref:`NXgeometry`

    "Engineering" position of moderator

  **temperature_log**: :ref:`NXlog`

    log file of moderator temperature

  **pulse_shape**: :ref:`NXdata`

    moderator pulse shape

**NXDL Source**:
  https://github.com/nexusformat/definitions/blob/master/base_classes/NXmoderator.nxdl.xml