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

.. index::
    ! NXfresnel_zone_plate (base class)
    ! fresnel zone plate (base class)
    see: fresnel zone plate (base class); NXfresnel_zone_plate

.. _NXfresnel_zone_plate:

====================
NXfresnel_zone_plate
====================

**Status**:

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

**Description**:

  A fresnel zone plate

**Symbols**:

  No symbol table

**Groups cited**:
  :ref:`NXtransformations`

.. index:: NXtransformations (base class); used in base class

**Structure**:

  .. index:: focus parameters (field)

  **focus_parameters[]**: :ref:`NX_FLOAT <NX_FLOAT>`

    list of polynomial coefficients describing the focal length of the zone plate, in increasing powers of photon energy,
    that describes the focal length of the zone plate (in microns) at an X-ray photon energy (in electron volts).

  .. index:: outer diameter (field)

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


  .. index:: outermost zone width (field)

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


  .. index:: central stop diameter (field)

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


  .. index:: fabrication (field)

  **fabrication**: :ref:`NX_CHAR <NX_CHAR>`

    how the zone plate was manufactured

    Any of these values: ``etched`` | ``plated`` | ``zone doubled`` | ``other``

  .. index:: zone height (field)

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


  .. index:: zone material (field)

  **zone_material**: :ref:`NX_CHAR <NX_CHAR>`

    Material of the zones themselves

  .. index:: zone support material (field)

  **zone_support_material**: :ref:`NX_CHAR <NX_CHAR>`

    Material present between the zones. This is usually only present for the "zone doubled" fabrication process

  .. index:: central stop material (field)

  **central_stop_material**: :ref:`NX_CHAR <NX_CHAR>`


  .. index:: central stop thickness (field)

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


  .. index:: mask thickness (field)

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


  .. index:: mask material (field)

  **mask_material**: :ref:`NX_CHAR <NX_CHAR>`

    If no mask is present, set mask_thickness to 0 and omit the mask_material field

  .. index:: support membrane material (field)

  **support_membrane_material**: :ref:`NX_CHAR <NX_CHAR>`


  .. index:: support membrane thickness (field)

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


  **(transformations)**: :ref:`NXtransformations`

    "Engineering" position of the fresnel zone plate

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