.. auto-generated by dev_tools.docs.nxdl from the NXDL source base_classes/NXsource.nxdl.xml -- DO NOT EDIT

.. index::
    ! NXsource (base class)
    ! source (base class)
    see: source (base class); NXsource

.. _NXsource:

========
NXsource
========

**Status**:

  base class, extends :ref:`NXcomponent`

**Description**:

  .. collapse:: Radiation source emitting a beam. ...

      Radiation source emitting a beam.

      Examples include particle sources (electrons, neutrons, protons) or sources for electromagnetic radiation (photons).
      This base class can also be used to describe neutron or x-ray storage ring/facilities.

**Symbols**:

  No symbol table

**Groups cited**:
  :ref:`NXaperture`, :ref:`NXdata`, :ref:`NXdeflector`, :ref:`NXelectromagnetic_lens`, :ref:`NXfabrication`, :ref:`NXgeometry`, :ref:`NXnote`, :ref:`NXoff_geometry`

.. index:: NXnote (base class); used in base class, NXdata (base class); used in base class, NXgeometry (base class); used in base class, NXaperture (base class); used in base class, NXelectromagnetic_lens (base class); used in base class, NXdeflector (base class); used in base class, NXfabrication (base class); used in base class, NXoff_geometry (base class); used in base class

**Structure**:

  .. _/NXsource/distance-field:

  .. index:: distance (field)

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

    .. collapse:: Effective distance from sample ...

        Effective distance from sample
        Distance as seen by radiation from sample. This number should be negative 
        to signify that it is upstream of the sample.

  .. _/NXsource/name-field:

  .. index:: name (field)

  **name**: (optional) :ref:`NX_CHAR <NX_CHAR>` :ref:`⤆ </NXcomponent/name-field>`

    Name of source

    .. _/NXsource/name@short_name-attribute:

    .. index:: short_name (field attribute)

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

      short name for source, perhaps the acronym

  .. _/NXsource/type-field:

  .. index:: type (field)

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

    .. collapse:: type of radiation source (pick one from the enumerated list and spell exactly) ...

        type of radiation source (pick one from the enumerated list and spell exactly)

        Any of these values or a custom value (if you use a custom value, also set @custom=True):

          * ``Spallation Neutron Source``

          * ``Pulsed Reactor Neutron Source``

          * ``Reactor Neutron Source``

          * ``Synchrotron X-ray Source``

          * ``Pulsed Muon Source``

          * ``Rotating Anode X-ray``

          * ``Fixed Tube X-ray``

          * ``UV Laser``

          * ``Free-Electron Laser``

          * ``Optical Laser``

          * ``Ion Source``

          * ``UV Plasma Source``

          * ``Metal Jet X-ray``

          * ``Laser``

          * ``Dye Laser``

          * ``Broadband Tunable Light Source``

          * ``Halogen Lamp``

          * ``LED``

          * ``Mercury Cadmium Telluride Lamp``

          * ``Deuterium Lamp``

          * ``Xenon Lamp``

          * ``Globar``


  .. _/NXsource/probe-field:

  .. index:: probe (field)

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

    .. collapse:: type of radiation probe (pick one from the enumerated list and spell exactly) ...

        type of radiation probe (pick one from the enumerated list and spell exactly)

        Any of these values:

          * ``neutron``

          * ``photon``

          * ``x-ray``

          * ``muon``

          * ``electron``

          * ``ultraviolet``

          * ``visible light``

          * ``positron``

          * ``proton``


  .. _/NXsource/power-field:

  .. index:: power (field)

  **power**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_POWER <NX_POWER>`} 

    Source power

  .. _/NXsource/emittance_x-field:

  .. index:: emittance_x (field)

  **emittance_x**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_EMITTANCE <NX_EMITTANCE>`} 

    Source emittance (nm-rad) in X (horizontal) direction.

  .. _/NXsource/emittance_y-field:

  .. index:: emittance_y (field)

  **emittance_y**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_EMITTANCE <NX_EMITTANCE>`} 

    Source emittance (nm-rad) in Y (horizontal) direction.

  .. _/NXsource/sigma_x-field:

  .. index:: sigma_x (field)

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

    particle beam size in x

  .. _/NXsource/sigma_y-field:

  .. index:: sigma_y (field)

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

    particle beam size in y

  .. _/NXsource/flux-field:

  .. index:: flux (field)

  **flux**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_FLUX <NX_FLUX>`} 

    Source intensity/area (example: s-1 cm-2)

  .. _/NXsource/energy-field:

  .. index:: energy (field)

  **energy**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_ENERGY <NX_ENERGY>`} 

    .. collapse:: Source energy. Typically, this would be the energy of ...

        Source energy. Typically, this would be the energy of
        the emitted beam. For storage rings, this would be
        the particle beam energy.

  .. _/NXsource/current-field:

  .. index:: current (field)

  **current**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_CURRENT <NX_CURRENT>`} 

    Accelerator, X-ray tube, or storage ring current

  .. _/NXsource/voltage-field:

  .. index:: voltage (field)

  **voltage**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_VOLTAGE <NX_VOLTAGE>`} 

    Accelerator voltage

  .. _/NXsource/frequency-field:

  .. index:: frequency (field)

  **frequency**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_FREQUENCY <NX_FREQUENCY>`} 

    Frequency of pulsed source

  .. _/NXsource/period-field:

  .. index:: period (field)

  **period**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_PERIOD <NX_PERIOD>`} 

    Period of pulsed source

  .. _/NXsource/target_material-field:

  .. index:: target_material (field)

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

    .. collapse:: Pulsed source target material ...

        Pulsed source target material

        Any of these values:

          * ``Ta``

          * ``W``

          * ``depleted_U``

          * ``enriched_U``

          * ``Hg``

          * ``Pb``

          * ``C``


  .. _/NXsource/number_of_bunches-field:

  .. index:: number_of_bunches (field)

  **number_of_bunches**: (optional) :ref:`NX_INT <NX_INT>` 

    For storage rings, the number of bunches in use.

  .. _/NXsource/bunch_length-field:

  .. index:: bunch_length (field)

  **bunch_length**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_TIME <NX_TIME>`} 

    For storage rings, temporal length of the bunch

  .. _/NXsource/bunch_distance-field:

  .. index:: bunch_distance (field)

  **bunch_distance**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_TIME <NX_TIME>`} 

    For storage rings, time between bunches

  .. _/NXsource/pulse_width-field:

  .. index:: pulse_width (field)

  **pulse_width**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_TIME <NX_TIME>`} 

    temporal width of source pulse

  .. _/NXsource/mode-field:

  .. index:: mode (field)

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

    .. collapse:: source operating mode ...

        source operating mode

        Any of these values or a custom value (if you use a custom value, also set @custom=True):

          * ``Single Bunch``: for storage rings

          * ``Multi Bunch``: for storage rings


  .. _/NXsource/top_up-field:

  .. index:: top_up (field)

  **top_up**: (optional) :ref:`NX_BOOLEAN <NX_BOOLEAN>` 

    Is the synchrotron operating in top_up mode?

  .. _/NXsource/last_fill-field:

  .. index:: last_fill (field)

  **last_fill**: (optional) :ref:`NX_NUMBER <NX_NUMBER>` {units=\ :ref:`NX_CURRENT <NX_CURRENT>`} 

    For storage rings, the current at the end of the most recent injection.

    .. _/NXsource/last_fill@time-attribute:

    .. index:: time (field attribute)

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

      date and time of the most recent injection.

  .. _/NXsource/wavelength-field:

  .. index:: wavelength (field)

  **wavelength**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_WAVELENGTH <NX_WAVELENGTH>`} 

    The wavelength of the radiation emitted by the source.

  .. _/NXsource/pulse_energy-field:

  .. index:: pulse_energy (field)

  **pulse_energy**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_ENERGY <NX_ENERGY>`} 

    For pulsed sources, the energy of a single pulse.

  .. _/NXsource/peak_power-field:

  .. index:: peak_power (field)

  **peak_power**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_POWER <NX_POWER>`} 

    .. collapse:: For pulsed sources, the pulse energy divided ...

        For pulsed sources, the pulse energy divided
        by the pulse duration

  .. _/NXsource/anode_material-field:

  .. index:: anode_material (field)

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

    Material of the anode (for X-ray tubes).

  .. _/NXsource/filament_current-field:

  .. index:: filament_current (field)

  **filament_current**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_CURRENT <NX_CURRENT>`} 

    Filament current (for X-ray tubes).

  .. _/NXsource/emission_current-field:

  .. index:: emission_current (field)

  **emission_current**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_CURRENT <NX_CURRENT>`} 

    Emission current of the generated beam.

  .. _/NXsource/gas_pressure-field:

  .. index:: gas_pressure (field)

  **gas_pressure**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_PRESSURE <NX_PRESSURE>`} 

    Gas pressure inside ionization source.

  .. _/NXsource/previous_source-field:

  .. index:: previous_source (field)

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

    .. collapse:: Single instance or list of instances of NXsource pointing to the sources from  ...

        Single instance or list of instances of NXsource pointing to the sources from which a beam originated to reach this source.
        This can be used, for example, for secondary sources to describe which other source(s) they are derived from.

        An example is the white light source in transient absorption spectroscopy, which is a supercontinuum crystal that is pumped by a
        another laser.

        In case of a primary source, this field should not be filled.

  .. _/NXsource/depends_on-field:

  .. index:: depends_on (field)

  **depends_on**: (optional) :ref:`NX_CHAR <NX_CHAR>` :ref:`⤆ </NXcomponent/depends_on-field>`

    .. collapse:: The reference point of the source plane is its center in the x and y axis. The ...

        The reference point of the source plane is its center in the x and y axis. The source is considered infinitely thin in the
        z axis.

        .. image:: source/source.png
          :width: 40%


  .. _/NXsource/notes-group:

  **notes**: (optional) :ref:`NXnote` :ref:`⤆ </NXobject/NOTE-group>`

    .. collapse:: any source/facility related messages/events that  ...

        any source/facility related messages/events that 
        occurred during the experiment

  .. _/NXsource/bunch_pattern-group:

  **bunch_pattern**: (optional) :ref:`NXdata` :ref:`⤆ </NXobject/DATA-group>`

    .. collapse:: For storage rings, description of the bunch pattern.   ...

        For storage rings, description of the bunch pattern.  
        This is useful to describe irregular bunch patterns.

    .. _/NXsource/bunch_pattern/title-field:

    .. index:: title (field)

    **title**: (optional) :ref:`NX_CHAR <NX_CHAR>` :ref:`⤆ </NXdata/title-field>`

      name of the bunch pattern

  .. _/NXsource/pulse_shape-group:

  **pulse_shape**: (optional) :ref:`NXdata` :ref:`⤆ </NXobject/DATA-group>`

    source pulse shape

  .. _/NXsource/geometry-group:

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


    .. index:: deprecated


    **DEPRECATED**: Use the field `depends_on` and :ref:`NXtransformations` to position the source and NXoff_geometry to describe its shape instead

    "Engineering" location of source.

  .. _/NXsource/APERTURE-group:

  :bolditalic:`APERTURE`: (optional) :ref:`NXaperture` 

    The size and position of an aperture inside the source.

  .. _/NXsource/ELECTROMAGNETIC_LENS-group:

  :bolditalic:`ELECTROMAGNETIC_LENS`: (optional) :ref:`NXelectromagnetic_lens` 

    Individual electromagnetic lenses inside the source.

  .. _/NXsource/DEFLECTOR-group:

  :bolditalic:`DEFLECTOR`: (optional) :ref:`NXdeflector` 

    Deflectors inside the source.

  .. _/NXsource/FABRICATION-group:

  :bolditalic:`FABRICATION`: (optional) :ref:`NXfabrication` :ref:`⤆ </NXcomponent/FABRICATION-group>`


  .. _/NXsource/OFF_GEOMETRY-group:

  :bolditalic:`OFF_GEOMETRY`: (optional) :ref:`NXoff_geometry` 

    This group describes the shape of the beam line component

  .. _/NXsource/distribution-group:

  **distribution**: (optional) :ref:`NXdata` :ref:`⤆ </NXobject/DATA-group>`

    The wavelength or energy distribution of the source


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

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


* :ref:`/NXsource/anode_material-field </NXsource/anode_material-field>`
* :ref:`/NXsource/APERTURE-group </NXsource/APERTURE-group>`
* :ref:`/NXsource/bunch_distance-field </NXsource/bunch_distance-field>`
* :ref:`/NXsource/bunch_length-field </NXsource/bunch_length-field>`
* :ref:`/NXsource/bunch_pattern-group </NXsource/bunch_pattern-group>`
* :ref:`/NXsource/bunch_pattern/title-field </NXsource/bunch_pattern/title-field>`
* :ref:`/NXsource/current-field </NXsource/current-field>`
* :ref:`/NXsource/DEFLECTOR-group </NXsource/DEFLECTOR-group>`
* :ref:`/NXsource/depends_on-field </NXsource/depends_on-field>`
* :ref:`/NXsource/distance-field </NXsource/distance-field>`
* :ref:`/NXsource/distribution-group </NXsource/distribution-group>`
* :ref:`/NXsource/ELECTROMAGNETIC_LENS-group </NXsource/ELECTROMAGNETIC_LENS-group>`
* :ref:`/NXsource/emission_current-field </NXsource/emission_current-field>`
* :ref:`/NXsource/emittance_x-field </NXsource/emittance_x-field>`
* :ref:`/NXsource/emittance_y-field </NXsource/emittance_y-field>`
* :ref:`/NXsource/energy-field </NXsource/energy-field>`
* :ref:`/NXsource/FABRICATION-group </NXsource/FABRICATION-group>`
* :ref:`/NXsource/filament_current-field </NXsource/filament_current-field>`
* :ref:`/NXsource/flux-field </NXsource/flux-field>`
* :ref:`/NXsource/frequency-field </NXsource/frequency-field>`
* :ref:`/NXsource/gas_pressure-field </NXsource/gas_pressure-field>`
* :ref:`/NXsource/geometry-group </NXsource/geometry-group>`
* :ref:`/NXsource/last_fill-field </NXsource/last_fill-field>`
* :ref:`/NXsource/last_fill@time-attribute </NXsource/last_fill@time-attribute>`
* :ref:`/NXsource/mode-field </NXsource/mode-field>`
* :ref:`/NXsource/name-field </NXsource/name-field>`
* :ref:`/NXsource/name@short_name-attribute </NXsource/name@short_name-attribute>`
* :ref:`/NXsource/notes-group </NXsource/notes-group>`
* :ref:`/NXsource/number_of_bunches-field </NXsource/number_of_bunches-field>`
* :ref:`/NXsource/OFF_GEOMETRY-group </NXsource/OFF_GEOMETRY-group>`
* :ref:`/NXsource/peak_power-field </NXsource/peak_power-field>`
* :ref:`/NXsource/period-field </NXsource/period-field>`
* :ref:`/NXsource/power-field </NXsource/power-field>`
* :ref:`/NXsource/previous_source-field </NXsource/previous_source-field>`
* :ref:`/NXsource/probe-field </NXsource/probe-field>`
* :ref:`/NXsource/pulse_energy-field </NXsource/pulse_energy-field>`
* :ref:`/NXsource/pulse_shape-group </NXsource/pulse_shape-group>`
* :ref:`/NXsource/pulse_width-field </NXsource/pulse_width-field>`
* :ref:`/NXsource/sigma_x-field </NXsource/sigma_x-field>`
* :ref:`/NXsource/sigma_y-field </NXsource/sigma_y-field>`
* :ref:`/NXsource/target_material-field </NXsource/target_material-field>`
* :ref:`/NXsource/top_up-field </NXsource/top_up-field>`
* :ref:`/NXsource/type-field </NXsource/type-field>`
* :ref:`/NXsource/voltage-field </NXsource/voltage-field>`
* :ref:`/NXsource/wavelength-field </NXsource/wavelength-field>`

**NXDL Source**:
  https://github.com/FAIRmat-NFDI/nexus_definitions/tree/fairmat/base_classes/NXsource.nxdl.xml