.. 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`

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


  .. index:: outermost_zone_width (field)

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


  .. index:: central_stop_diameter (field)

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


  .. index:: fabrication (field)

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


  .. index:: zone_material (field)

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

    Material of the zones themselves

  .. index:: zone_support_material (field)

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


  .. index:: central_stop_thickness (field)

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


  .. index:: mask_thickness (field)

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


  .. index:: mask_material (field)

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


  .. index:: support_membrane_thickness (field)

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


  **(transformations)**: (optional) :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