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:
NXdata, NXshape, NXtransformations

Structure:

angles[2]: (optional) 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[]: (optional) 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: (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 | argon

substrate_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

shape: (optional) NXshape

A NXshape group describing the shape of the mirror

figure_data: (optional) NXdata

Numerical description of the surface figure of the mirror.

(transformations): (optional) NXtransformations

“Engineering” position of the grating
NXDL Source:
https://github.com/nexusformat/definitions/blob/master/base_classes/NXgrating.nxdl.xml