3.3.3.15. NXelectronanalyser

Status:

base class, extends NXobject

Description:

Subclass of NXinstrument to describe a photoelectron analyser.

Symbols:

The symbols used in the schema to specify e.g. dimensions of arrays

nfa: Number of fast axes (axes acquired symultaneously, without scanning a pysical quantity)

nsa: Number of slow axes (axes acquired scanning a pysical quantity)

Groups cited:

NXcollectioncolumn, NXdeflector, NXdetector, NXenergydispersion, NXlens_em, NXspindispersion, NXtransformations

Structure:

description: (optional) NX_CHAR

Free text description of the type of the detector

name: (optional) NX_CHAR

Name or model of the equipment

@short_name: (optional) NX_CHAR

Acronym or other shorthand name

energy_resolution: (optional) NX_FLOAT {units=NX_ENERGY}

Energy resolution of the electron analyser (FWHM of gaussian broadening)

momentum_resolution: (optional) NX_FLOAT {units=NX_WAVENUMBER}

Momentum resolution of the electron analyser (FWHM)

angular_resolution: (optional) NX_FLOAT {units=NX_ANGLE}

Angular resolution of the electron analyser (FWHM)

spatial_resolution: (optional) NX_FLOAT {units=NX_LENGTH}

Spatial resolution of the electron analyser (Airy disk radius)

fast_axes: (optional) NX_CHAR (Rank: 1, Dimensions: [nfa])

List of the axes that are acquired simultaneously by the detector. These refer only to the experimental variables recorded by the electron analyser. Other variables such as temperature, manipulator angles etc. are labeled as fast or slow in the data.

Examples

Mode

fast_axes

slow_axes

Hemispherical in ARPES mode

[‘energy’, ‘kx’]

Hemispherical with channeltron, sweeping energy mode

["energy"]

Tof

[‘energy’, ‘kx’, ‘ky’]

Momentum microscope, spin-resolved

[‘energy’, ‘kx’, ‘ky’]

[‘spin up-down’, ‘spin left-right’]

Axes may be less abstract than this, i.e. [‘detector_x’, ‘detector_y’]. If energy_scan_mode=sweep, fast_axes: [‘energy’, ‘kx’]; slow_axes: [‘energy’] is allowed.

slow_axes: (optional) NX_CHAR (Rank: 1, Dimensions: [nsa])

List of the axes that are acquired by scanning a physical parameter, listed in order of decreasing speed. See fast_axes for examples.

depends_on: (optional) NX_CHAR

Refers to the last transformation specifying the positon of the manipulator in the NXtransformations chain.

TRANSFORMATIONS: (optional) NXtransformations

Collection of axis-based translations and rotations to describe the location and geometry of the manipulator 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.

COLLECTIONCOLUMN: (optional) NXcollectioncolumn

Describes the electron collection (spatial and momentum imaging) column

ENERGYDISPERSION: (optional) NXenergydispersion

Describes the energy dispersion section

SPINDISPERSION: (optional) NXspindispersion

Describes the spin dispersion section

DETECTOR: (optional) NXdetector

Describes the electron detector

DEFLECTOR: (optional) NXdeflector

Deflectors outside the main optics ensambles described by the subclasses

LENS_EM: (optional) NXlens_em

Individual lenses outside the main optics ensambles described by the subclasses

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/contributed_definitions/NXelectronanalyser.nxdl.xml