# 3.3.1.9. 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 ...

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_CHARAny 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_CHARname of absorbing material

transmitting_material: (optional) NX_CHARname of transmitting material

depends_on: (optional) NX_CHAR

GEOMETRY: (optional) NXgeometry

DEPRECATED: Use the field depends_on and NXtransformations to position the collimator and NXoff_geometry to describe its shape insteadposition, shape and size

frequency_log: (optional) NXlogLog of frequency

OFF_GEOMETRY: (optional) NXoff_geometryThis group describes the shape of the beam line component

TRANSFORMATIONS: (optional) NXtransformations## This is the group recommended for holding the chain of translation ...

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.