3.3.1.25. NXgrating¶
Status:
base class, extends NXobject
Description:
A diffraction grating, as could be used in a soft X-ray monochromator
Symbols:
No symbol table
- Groups cited:
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.
angles: (optional) NX_FLOAT (Rank: 1, Dimensions: [2]) {units=NX_ANGLE}
Blaze or trapezoidal angles, with the angle of the upstream facing edge listed first. Blazed gratings can be identified by the low value of the first-listed angle.
period: (optional) NX_FLOAT (Rank: 1) {units=NX_LENGTH}
List of polynomial coefficients describing the spatial separation of lines/grooves as a function of position along the grating, in increasing powers of position. Gratings which do not have variable line spacing will only have a single coefficient (constant).
duty_cycle: (optional) NX_FLOAT {units=NX_UNITLESS}
depth: (optional) NX_FLOAT {units=NX_LENGTH}
diffraction_order: (optional) NX_INT {units=NX_UNITLESS}
deflection_angle: (optional) NX_FLOAT {units=NX_ANGLE}
Angle between the incident beam and the utilised outgoing beam.
interior_atmosphere: (optional) NX_CHAR
Any of these values:
vacuum|helium|argonsubstrate_material: (optional) NX_CHAR
substrate_density: (optional) NX_FLOAT {units=NX_MASS_DENSITY}
substrate_thickness: (optional) NX_FLOAT {units=NX_LENGTH}
coating_material: (optional) NX_CHAR
substrate_roughness: (optional) NX_FLOAT {units=NX_LENGTH}
coating_roughness: (optional) NX_FLOAT {units=NX_LENGTH}
layer_thickness: (optional) NX_FLOAT {units=NX_LENGTH}
An array describing the thickness of each layer
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.
shape: (optional) NXshape
DEPRECATED: Use NXoff_geometry to describe the shape of grating
A NXshape group describing the shape of the mirror
figure_data: (optional) NXdata
Numerical description of the surface figure of the mirror.
OFF_GEOMETRY: (optional) NXoff_geometry
This group describes the shape of the beam line component
TRANSFORMATIONS: (optional) NXtransformations
“Engineering” position of the grating Transformations used by this component to define its position and orientation.
Hypertext Anchors¶
List of hypertext anchors for all groups, fields, attributes, and links defined in this class.