4.3.1.23. NXfresnel_zone_plate

Status:

base class, extends NXobject

Description:

A fresnel zone plate

Symbols:

No symbol table

Groups cited:

NXtransformations

Structure:

@default: (optional) NX_CHAR

Declares which child group contains a path leading to a 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.

focus_parameters: (optional) NX_FLOAT (Rank: 1)

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).

outer_diameter: (optional) NX_FLOAT {units=NX_LENGTH}

outermost_zone_width: (optional) NX_FLOAT {units=NX_LENGTH}

central_stop_diameter: (optional) NX_FLOAT {units=NX_LENGTH}

fabrication: (optional) NX_CHAR

how the zone plate was manufactured

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

zone_height: (optional) NX_FLOAT {units=NX_LENGTH}

zone_material: (optional) NX_CHAR

Material of the zones themselves

zone_support_material: (optional) NX_CHAR

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

central_stop_material: (optional) NX_CHAR

central_stop_thickness: (optional) NX_FLOAT {units=NX_LENGTH}

mask_thickness: (optional) NX_FLOAT {units=NX_LENGTH}

mask_material: (optional) NX_CHAR

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

support_membrane_material: (optional) NX_CHAR

support_membrane_thickness: (optional) NX_FLOAT {units=NX_LENGTH}

depends_on: (optional) NX_CHAR

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.

TRANSFORMATIONS: (optional) NXtransformations

“Engineering” position of the fresnel zone plate

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.

NXDL Source:

https://github.com/nexusformat/definitions/blob/main/base_classes/NXfresnel_zone_plate.nxdl.xml