3.3.1.25. NXgrating

Status:

base class, extends NXobject, version 1.0

Description:

A diffraction grating, as could be used in a soft X-ray monochromator

Symbols:

No symbol table

Groups cited:

NXdata, NXshape, NXtransformations

Structure:

angles[2]: NX_FLOAT {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[]: NX_FLOAT {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: NX_FLOAT {units=NX_UNITLESS}

depth: NX_FLOAT {units=NX_LENGTH}

diffraction_order: NX_INT {units=NX_UNITLESS}

deflection_angle: NX_FLOAT {units=NX_ANGLE}

Angle between the incident beam and the utilised outgoing beam.

interior_atmosphere: NX_CHAR

Any of these values: vacuum | helium | argon

substrate_material: NX_CHAR

substrate_density: NX_FLOAT {units=NX_MASS_DENSITY}

substrate_thickness: NX_FLOAT {units=NX_LENGTH}

coating_material: NX_CHAR

substrate_roughness: NX_FLOAT {units=NX_LENGTH}

coating_roughness: NX_FLOAT {units=NX_LENGTH}

layer_thickness: NX_FLOAT {units=NX_LENGTH}

An array describing the thickness of each layer

shape: NXshape

A NXshape group describing the shape of the mirror

figure_data: NXdata

Numerical description of the surface figure of the mirror.

(transformations): NXtransformations

“Engineering” position of the grating

NXDL Source:

https://github.com/nexusformat/definitions/blob/master/base_classes/NXgrating.nxdl.xml