2.3.3.1.9. NXcollimator

Status:

base class, extends NXobject

Description:

A beamline collimator.

Symbols:

No symbol table

Groups cited:

NXgeometry, NXlog, NXoff_geometry, NXtransformations

Structure:

@default: (optional) NX_CHAR

Declares which child group contains a path leading ...

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.

type: (optional) NX_CHAR

Any of these values: Soller | radial | oscillating | honeycomb

soller_angle: (optional) NX_FLOAT {units=NX_ANGLE}

Angular divergence of Soller collimator

divergence_x: (optional) NX_FLOAT {units=NX_ANGLE}

divergence of collimator in local x direction

divergence_y: (optional) NX_FLOAT {units=NX_ANGLE}

divergence of collimator in local y direction

frequency: (optional) NX_FLOAT {units=NX_FREQUENCY}

Frequency of oscillating collimator

blade_thickness: (optional) NX_FLOAT {units=NX_LENGTH}

blade thickness

blade_spacing: (optional) NX_FLOAT {units=NX_LENGTH}

blade spacing

absorbing_material: (optional) NX_CHAR

name of absorbing material

transmitting_material: (optional) NX_CHAR

name of transmitting material

depends_on: (optional) NX_CHAR

NeXus positions components by applying a set of translations and rotations ...

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.

Assuming a collimator with a “flat” entry surface, the reference plane is the plane which contains this surface. The reference point of the collimator in the x and y axis is the centre of the collimator entry surface on that plane. The reference plane is orthogonal to the z axis and the location of this plane is the reference point on the z axis. The collimator faces negative z values.

../../_images/collimator.png

GEOMETRY: (optional) NXgeometry

DEPRECATED: Use the field depends_on and NXtransformations to position the collimator and NXoff_geometry to describe its shape instead

position, shape and size

frequency_log: (optional) NXlog

Log of frequency

OFF_GEOMETRY: (optional) NXoff_geometry

This group describes the shape of the beam line component

TRANSFORMATIONS: (optional) NXtransformations

Hypertext Anchors

List of hypertext anchors for all groups, fields, attributes, and links defined in this class.

NXDL Source:

https://github.com/FAIRmat-NFDI/nexus_definitions/tree/fairmat/base_classes/NXcollimator.nxdl.xml