4.3.1.9. NXcollimator¶
Status:
base class, extends NXobject
Description:
A beamline collimator.
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.
type: (optional) NX_CHAR
Any of these values:
Soller|radial|oscillating|honeycombsoller_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 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.
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
This is the group recommended for holding the chain of translation and rotation operations necessary to position the component within the instrument. The dependency chain may however traverse similar groups in other component groups.
Hypertext Anchors¶
List of hypertext anchors for all groups, fields, attributes, and links defined in this class.