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

.. index::
    ! NXxas (application definition)
    ! xas (application definition)
    see: xas (application definition); NXxas

.. _NXxas:

=====
NXxas
=====

**Status**:

  application definition, extends :ref:`NXobject`

**Description**:

  This is an application definition for raw data from an X-ray absorption spectroscopy experiment.

  This is essentially a scan on energy versus incoming/ 
  absorbed beam.

**Symbols**:

  No symbol table

**Groups cited**:
  :ref:`NXdata`, :ref:`NXdetector`, :ref:`NXentry`, :ref:`NXinstrument`, :ref:`NXmonitor`, :ref:`NXmonochromator`, :ref:`NXsample`, :ref:`NXsource`

.. index:: NXentry (base class); used in application definition, NXinstrument (base class); used in application definition, NXsource (base class); used in application definition, NXmonochromator (base class); used in application definition, NXdetector (base class); used in application definition, NXsample (base class); used in application definition, NXmonitor (base class); used in application definition, NXdata (base class); used in application definition

**Structure**:

  **(entry)**: (required) :ref:`NXentry`


    .. index:: entry (group attribute)

    **@entry**: (required) :ref:`NX_CHAR <NX_CHAR>`

      NeXus convention is to use "entry1", "entry2", ... 
      for analysis software to locate each entry.

    .. index:: title (field)

    **title**: (required) :ref:`NX_CHAR <NX_CHAR>`


    .. index:: start_time (field)

    **start_time**: (required) :ref:`NX_DATE_TIME <NX_DATE_TIME>`


    .. index:: definition (field)

    **definition**: (required) :ref:`NX_CHAR <NX_CHAR>`

      Official NeXus NXDL schema to which this file conforms

      Obligatory value:  ``NXxas``

    **(instrument)**: (required) :ref:`NXinstrument`


      **(source)**: (required) :ref:`NXsource`


        .. index:: type (field)

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


        .. index:: name (field)

        **name**: (required) :ref:`NX_CHAR <NX_CHAR>`


        .. index:: probe (field)

        **probe**: (required) :ref:`NX_CHAR <NX_CHAR>`


          Obligatory value:  ``x-ray``

      **monochromator**: (required) :ref:`NXmonochromator`


        .. index:: energy (field)

        **energy[np]**: (required) :ref:`NX_FLOAT <NX_FLOAT>`


      **incoming_beam**: (required) :ref:`NXdetector`


        .. index:: data (field)

        **data[np]**: (required) :ref:`NX_INT <NX_INT>`


      **absorbed_beam**: (required) :ref:`NXdetector`


        .. index:: data (field)

        **data[np]**: (required) :ref:`NX_INT <NX_INT>`

          mark this field with attribute  ``signal=1``

    **(sample)**: (required) :ref:`NXsample`


      .. index:: name (field)

      **name**: (required) :ref:`NX_CHAR <NX_CHAR>`

        Descriptive name of sample

    **(monitor)**: (required) :ref:`NXmonitor`


      .. index:: mode (field)

      **mode**: (required) :ref:`NX_CHAR <NX_CHAR>`

        Count to a preset value based on either clock time (timer)
        or received monitor counts (monitor).

        Any of these values: ``monitor`` | ``timer``

      .. index:: preset (field)

      **preset**: (required) :ref:`NX_FLOAT <NX_FLOAT>`

        preset value for time or monitor

      .. index:: data (field)

      **data[np]**: (required) :ref:`NX_INT <NX_INT>`


    **(data)**: (required) :ref:`NXdata`


      **energy** --> /entry/instrument/monochromator/energy


      **absorbed_beam** --> /entry/instrument/absorbed_beam/data


**NXDL Source**:
  https://github.com/nexusformat/definitions/blob/master/applications/NXxas.nxdl.xml