3.3.1.28. NXinsertion_device

Status:

base class, extends NXobject

Description:

An insertion device, as used in a synchrotron light source.

Symbols:

No symbol table

Groups cited:

NXdata, NXgeometry, 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: undulator | wiggler

gap: (optional) NX_FLOAT {units=NX_LENGTH}

separation between opposing pairs of magnetic poles

taper: (optional) NX_FLOAT {units=NX_ANGLE}

angular of gap difference between upstream and downstream ends of the insertion device

phase: (optional) NX_FLOAT {units=NX_ANGLE}

poles: (optional) NX_INT {units=NX_UNITLESS}

number of poles

magnetic_wavelength: (optional) NX_FLOAT {units=NX_WAVELENGTH}

k: (optional) NX_FLOAT {units=NX_DIMENSIONLESS}

beam displacement parameter

length: (optional) NX_FLOAT {units=NX_LENGTH}

length of insertion device

power: (optional) NX_FLOAT {units=NX_POWER}

total power delivered by insertion device

energy: (optional) NX_FLOAT {units=NX_ENERGY}

energy of peak intensity in output spectrum

bandwidth: (optional) NX_FLOAT {units=NX_ENERGY}

bandwidth of peak energy

harmonic: (optional) NX_INT {units=NX_UNITLESS}

harmonic number of peak

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.

spectrum: (optional) NXdata

spectrum of insertion device

GEOMETRY: (optional) NXgeometry

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

“Engineering” position of insertion device

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/nexusformat/definitions/blob/main/base_classes/NXinsertion_device.nxdl.xml