NXaperture

Status:

base class, extends NXobject

Description:

A beamline aperture

Symbols:

No symbol table

Groups cited:

NXgeometry, NXnote, NXpositioner, 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.

material: (optional) NX_CHAR

Absorbing material of the aperture.

description: (optional) NX_CHAR

Description of the aperture.

shape: (optional) NX_CHAR

Shape of the aperture.

Any of these values:

  • straight slit

  • curved slit

  • pinhole

  • circle

  • square

  • hexagon

  • octagon

  • bladed

  • open

  • grid

size: (optional) NX_NUMBER {units=NX_LENGTH}

The relevant dimension for the aperture, i.e. slit width, pinhole and iris diameter

depends_on: (optional) NX_CHAR

Specifies the position of the aperture by pointing to the last transformation in the transformation chain in the NXtransformations group.

TRANSFORMATIONS: (optional) NXtransformations

Collection of axis-based translations and rotations to describe the location and geometry of the deflector as a component in the instrument. Conventions from the NXtransformations base class are used. In principle, the McStas coordinate system is used. The first transformation has to point either to another component of the system or . (for pointing to the reference frame) to relate it relative to the experimental setup. Typically, the components of a system should all be related relative to each other and only one component should relate to the reference coordinate system.

POSITIONER: (optional) NXpositioner

Stores the raw positions of aperture motors.

GEOMETRY: (optional) NXgeometry

Location and shape of the aperture.

BLADE_GEOMETRY: (optional) NXgeometry

Location and shape of each blade.

NOTE: (optional) NXnote

Describes any additional information.

Hypertext Anchors

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

NXDL Source:

https://github.com/FAIRmat-Experimental/nexus_definitions/tree/fairmat/contributed_definitions/NXaperture.nxdl.xml