.. auto-generated by dev_tools.docs.nxdl from the NXDL source base_classes/NXmoderator.nxdl.xml -- DO NOT EDIT .. index:: ! NXmoderator (base class) ! moderator (base class) see: moderator (base class); NXmoderator .. _NXmoderator: =========== NXmoderator =========== .. Contributors List .. |contrib_name| replace:: Aaron Brewster|phyy-nx|https://avatars.githubusercontent.com/u/13471434?v=4|2022-06-15 .. |contrib_name| replace:: Pete R Jemian|prjemian|https://avatars.githubusercontent.com/u/2279984?v=4|2022-01-28 .. |contrib_name| replace:: Peter Chang|PeterC-DLS|https://avatars.githubusercontent.com/u/1381719?v=4|2020-10-20 .. |contrib_name| replace:: Tobias Richter|zjttoefs|https://avatars.githubusercontent.com/u/856440?v=4|2018-05-15 **Status**: base class, extends :ref:`NXobject` **Description**: A neutron moderator **Symbols**: No symbol table **Groups cited**: :ref:`NXdata`, :ref:`NXgeometry`, :ref:`NXlog`, :ref:`NXoff_geometry`, :ref:`NXtransformations` .. index:: NXgeometry (base class); used in base class, NXlog (base class); used in base class, NXdata (base class); used in base class, NXoff_geometry (base class); used in base class, NXtransformations (base class); used in base class **Structure**: .. _/NXmoderator@default-attribute: .. index:: default (file attribute) **@default**: (optional) :ref:`NX_CHAR ` .. collapse:: Declares which child group contains a path leading ... .. 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. .. _/NXmoderator/distance-field: .. index:: distance (field) **distance**: (optional) :ref:`NX_FLOAT ` {units=\ :ref:`NX_LENGTH `} .. collapse:: Effective distance as seen by measuring radiation. ... Effective distance as seen by measuring radiation. Note, it is recommended to use NXtransformations instead. .. _/NXmoderator/type-field: .. index:: type (field) **type**: (optional) :ref:`NX_CHAR ` Any of these values: * ``H20`` * ``D20`` * ``Liquid H2`` * ``Liquid CH4`` * ``Liquid D2`` * ``Solid D2`` * ``C`` * ``Solid CH4`` * ``Solid H2`` .. _/NXmoderator/poison_depth-field: .. index:: poison_depth (field) **poison_depth**: (optional) :ref:`NX_FLOAT ` {units=\ :ref:`NX_LENGTH `} .. _/NXmoderator/coupled-field: .. index:: coupled (field) **coupled**: (optional) :ref:`NX_BOOLEAN ` whether the moderator is coupled .. _/NXmoderator/coupling_material-field: .. index:: coupling_material (field) **coupling_material**: (optional) :ref:`NX_CHAR ` The material used for coupling. Usually Cd. .. _/NXmoderator/poison_material-field: .. index:: poison_material (field) **poison_material**: (optional) :ref:`NX_CHAR ` Any of these values: ``Gd`` | ``Cd`` .. _/NXmoderator/temperature-field: .. index:: temperature (field) **temperature**: (optional) :ref:`NX_FLOAT ` {units=\ :ref:`NX_TEMPERATURE `} average/nominal moderator temperature .. _/NXmoderator/depends_on-field: .. index:: depends_on (field) **depends_on**: (optional) :ref:`NX_CHAR ` .. collapse:: NeXus positions components by applying a set of translations and rotations ... NeXus positions components by applying a set of translations and rotations to apply to the component starting from 0, 0, 0. The order of these operations is critical and forms what NeXus calls a dependency chain. The depends_on field defines the path to the top most operation of the dependency chain or the string "." if located in the origin. Usually these operations are stored in a NXtransformations group. But NeXus allows them to be stored anywhere. The reference point of the moderator is its center in the x and y axis. The reference point on the z axis is the surface of the moderator pointing towards the source (the negative part of the z axis). .. image:: moderator/moderator.png :width: 40% .. _/NXmoderator/GEOMETRY-group: **GEOMETRY**: (optional) :ref:`NXgeometry` .. index:: deprecated **DEPRECATED**: Use the field `depends_on` and :ref:`NXtransformations` to position the moderator and NXoff_geometry to describe its shape instead "Engineering" position of moderator .. _/NXmoderator/temperature_log-group: **temperature_log**: (optional) :ref:`NXlog` log file of moderator temperature .. _/NXmoderator/pulse_shape-group: **pulse_shape**: (optional) :ref:`NXdata` moderator pulse shape .. _/NXmoderator/OFF_GEOMETRY-group: **OFF_GEOMETRY**: (optional) :ref:`NXoff_geometry` This group describes the shape of the moderator .. _/NXmoderator/TRANSFORMATIONS-group: **TRANSFORMATIONS**: (optional) :ref:`NXtransformations` .. collapse:: This is the group recommended for holding the chain of translation ... This is the group recommended for holding the chain of translation and rotation operations necessary to position the component within the instrument. The dependency chain may however traverse similar groups in other component groups. Hypertext Anchors ----------------- List of hypertext anchors for all groups, fields, attributes, and links defined in this class. * :ref:`/NXmoderator/coupled-field ` * :ref:`/NXmoderator/coupling_material-field ` * :ref:`/NXmoderator/depends_on-field ` * :ref:`/NXmoderator/distance-field ` * :ref:`/NXmoderator/GEOMETRY-group ` * :ref:`/NXmoderator/OFF_GEOMETRY-group ` * :ref:`/NXmoderator/poison_depth-field ` * :ref:`/NXmoderator/poison_material-field ` * :ref:`/NXmoderator/pulse_shape-group ` * :ref:`/NXmoderator/temperature-field ` * :ref:`/NXmoderator/temperature_log-group ` * :ref:`/NXmoderator/TRANSFORMATIONS-group ` * :ref:`/NXmoderator/type-field ` * :ref:`/NXmoderator@default-attribute ` **NXDL Source**: https://github.com/nexusformat/definitions/blob/main/base_classes/NXmoderator.nxdl.xml