2.3.3.3.163. NXmpes

Status:

application definition, extends NXobject

Description:

This is the most general application definition for ...

This is the most general application definition for photoemission experiments.

Groups and fields are named according to the ISO 18115-1:2023 specification as well as the IUPAC Recommendations 2020.

Symbols:

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

n_transmission_function: Number of data points in the transmission function.

Groups cited:

NXactuator, NXaperture, NXbeam, NXcalibration, NXcollectioncolumn, NXcoordinate_system_set, NXdata, NXdetector, NXelectron_level, NXelectronanalyser, NXenergydispersion, NXentry, NXenvironment, NXfabrication, NXhistory, NXidentifier, NXinstrument, NXlog, NXmanipulator, NXphysical_process, NXpid, NXprocess_mpes, NXresolution, NXsample, NXsensor, NXsource, NXsubstance, NXuser

Structure:

ENTRY: (required) NXentry

definition: (required) NX_CHAR ⤆

Obligatory value: NXmpes

@version: (required) NX_CHAR ⤆

title: (required) NX_CHAR ⤆

start_time: (required) NX_DATE_TIME ⤆

Datetime of the start of the measurement. ...

Datetime of the start of the measurement. Should be a ISO8601 date/time stamp. It is recommended to add an explicit time zone, otherwise the local time zone is assumed per ISO8601.

end_time: (recommended) NX_DATE_TIME ⤆

Datetime of the end of the measurement. ...

Datetime of the end of the measurement. Should be a ISO8601 date/time stamp. It is recommended to add an explicit time zone, otherwise the local time zone is assumed per ISO8601.

method: (recommended) NX_CHAR

Name of the experimental method. ...

Name of the experimental method.

If applicable, this name should match the terms given by Clause 11 of the ISO 18115-1:2023 specification.

Examples include:

  • X-ray photoelectron spectroscopy (XPS)

  • angle-resolved X-ray photoelectron spectroscopy (ARXPS)

  • ultraviolet photoelectron spectroscopy (UPS)

  • angle-resolved photoelectron spectroscopy (ARPES)

  • hard X-ray photoemission spectroscopy (HAXPES)

  • near ambient pressure X-ray photoelectron spectroscopy (NAPXPS)

  • photoelectron emission microscopy (PEEM)

  • electron spectroscopy for chemical analysis (ESCA)

  • time-resolved angle-resolved X-ray photoelectron spectroscopy (trARPES)

  • spin-resolved angle-resolved X-ray photoelectron spectroscopy (spin-ARPES)

  • momentum microscopy

geometries: (optional) NXcoordinate_system_set

Description of one or more coordinate systems that are specific to the setup ...

Description of one or more coordinate systems that are specific to the setup and the measurement geometry.

USER: (recommended) NXuser ⤆

Contact information of at least the user of the instrument or the investigat ...

Contact information of at least the user of the instrument or the investigator who performed this experiment. Adding multiple users if relevant is recommended.

name: (required) NX_CHAR ⤆

Name of the user.

affiliation: (required) NX_CHAR ⤆

Name of the affiliation of the user at the time when the experiment was ...

Name of the affiliation of the user at the time when the experiment was performed.

INSTRUMENT: (required) NXinstrument ⤆

Description of the photoemission spectrometer and its individual parts. ...

Description of the photoemission spectrometer and its individual parts.

This concept is related to term 12.58 of the ISO 18115-1:2023 standard.

energy_resolution: (optional) NXresolution ⤆

Overall energy resolution of the photoemission instrument.

physical_quantity: (required) NX_CHAR ⤆

Obligatory value: energy

type: (recommended) NX_CHAR ⤆

resolution: (required) NX_FLOAT {units=NX_ENERGY} ⤆

Minimum distinguishable energy separation in the energy spectra. ...

Minimum distinguishable energy separation in the energy spectra.

This concept is related to term 10.24 of the ISO 18115-1:2023 standard.

relative_resolution: (optional) NX_FLOAT ⤆

Ratio of the energy resolution of the photoemission spectrometer at a sp ...

Ratio of the energy resolution of the photoemission spectrometer at a specified energy value to that energy value.

This concept is related to term 10.7 ff. of the ISO 18115-1:2023 standard.

device_information: (recommended) NXfabrication ⤆

vendor: (recommended) NX_CHAR ⤆

model: (recommended) NX_CHAR ⤆

identifier: (recommended) NXidentifier ⤆

sourceTYPE: (recommended) NXsource ⤆

A source used to generate a beam. Properties refer strictly to parameters ...

A source used to generate a beam. Properties refer strictly to parameters of the source, not of the output beam. For example, the energy of the source is not the optical power of the beam, but the energy of the electron beam in a synchrotron or similar.

Note that the uppercase notation in sourceTYPE means that multiple sources can be provided. The uppercase part can be substituted with any string that consists of alphanumeric characters, including both uppercase and lowercase letters from A to Z and numerical digits from 0 to 9. For example, in pump-probe experiments, it is possible to have both a source_probe and a source_pump.

type: (required) NX_CHAR ⤆

Any of these values:

  • Synchrotron X-ray Source

  • Rotating Anode X-ray

  • Fixed Tube X-ray

  • UV Laser

  • Free-Electron Laser

  • Optical Laser

  • UV Plasma Source

  • Metal Jet X-ray

  • HHG laser

  • UV lamp

  • Monochromatized electron source

  • other

type_other: (optional) NX_CHAR ⤆

Specification of type, may also go to name.

name: (recommended) NX_CHAR ⤆

probe: (optional) NX_CHAR ⤆

associated_beam: (required) NX_CHAR

A reference to a beam emitted by this source. ...

A reference to a beam emitted by this source. Should be named with the same appendix, e.g., for source_probe it should refer to beam_probe.

Example:

  • /entry/instrument/source_probe = /entry/instrument/beam_probe

device_information: (recommended) NXfabrication ⤆

vendor: (recommended) NX_CHAR ⤆

model: (recommended) NX_CHAR ⤆

identifier: (recommended) NXidentifier ⤆

beamTYPE: (required) NXbeam ⤆

Properties of the photon beam at a given location. ...

Properties of the photon beam at a given location. Should be named with the same appendix as sourceTYPE, e.g., for source_probe it should refer to beam_probe.

distance: (recommended) NX_NUMBER {units=NX_LENGTH}

Distance between the point where the current NXbeam instance is evaluati ...

Distance between the point where the current NXbeam instance is evaluating the beam properties and the point where the beam interacts with the sample. For photoemission, the latter is the point where the the centre of the beam touches the sample surface.

incident_energy: (required) NX_FLOAT {units=NX_ENERGY} ⤆

incident_energy_spread: (recommended) NX_NUMBER {units=NX_ENERGY} ⤆

incident_polarization: (recommended) NX_NUMBER {units=NX_ANY} ⤆

extent: (recommended) NX_FLOAT ⤆

associated_source: (recommended) NX_CHAR

The source that emitted this beam. ...

The source that emitted this beam. Should be named with the same appendix, e.g., for beam_probe it should refer to source_probe. This should be specified if an associated source exists.

Example:

  • /entry/instrument/beam_probe = /entry/instrument/source_probe

ELECTRONANALYSER: (required) NXelectronanalyser

description: (recommended) NX_CHAR ⤆

work_function: (recommended) NX_FLOAT {units=NX_ENERGY} ⤆

fast_axes: (recommended) NX_CHAR ⤆

slow_axes: (recommended) NX_CHAR ⤆

device_information: (recommended) NXfabrication ⤆

vendor: (recommended) NX_CHAR ⤆

model: (recommended) NX_CHAR ⤆

identifier: (recommended) NXidentifier ⤆

energy_resolution: (optional) NXresolution ⤆

type: (recommended) NX_CHAR ⤆

physical_quantity: (required) NX_CHAR ⤆

Obligatory value: energy

resolution: (required) NX_FLOAT ⤆

transmission_function: (optional) NXdata ⤆

COLLECTIONCOLUMN: (required) NXcollectioncolumn ⤆

scheme: (required) NX_CHAR ⤆

Scheme of the electron collection column. ...

Scheme of the electron collection column.

Any of these values:

  • angular dispersive

  • spatial dispersive

  • momentum dispersive

  • non-dispersive

lens_mode: (recommended) NX_CHAR ⤆

projection: (recommended) NX_CHAR ⤆

angular_acceptance: (optional) NX_FLOAT ⤆

spatial_acceptance: (optional) NX_FLOAT ⤆

field_aperture: (optional) NXaperture ⤆

The size and position of the field aperture inserted in the column. To ...

The size and position of the field aperture inserted in the column. To add additional or other apertures use the APERTURE group of NXcollectioncolumn.

contrast_aperture: (optional) NXaperture ⤆

The size and position of the contrast aperture inserted in the column. ...

The size and position of the contrast aperture inserted in the column. To add additional or other apertures use the APERTURE group of NXcollectioncolumn.

iris: (optional) NXaperture ⤆

Size, position and shape of the iris inserted in the column. ...

Size, position and shape of the iris inserted in the column.

The iris is an aperture in the lens with a variable diameter which can reduce the number of electrons entering the analyzer.

To add additional or other slits use the APERTURE group of NXcollectioncolumn.

device_information: (recommended) NXfabrication ⤆

vendor: (recommended) NX_CHAR ⤆

model: (recommended) NX_CHAR ⤆

identifier: (recommended) NXidentifier ⤆

ENERGYDISPERSION: (required) NXenergydispersion ⤆

scheme: (required) NX_CHAR ⤆

Any of these values:

  • tof

  • hemispherical

  • double hemispherical

  • cylindrical mirror

  • display mirror

  • retarding grid

pass_energy: (recommended) NX_FLOAT {units=NX_ENERGY} ⤆

Either `pass_energy` or `drift_energy` must be supplied. `pass_energy` ...

Either pass_energy or drift_energy must be supplied. pass_energy should be used when working with hemispherical analysers.

drift_energy: (recommended) NX_FLOAT {units=NX_ENERGY} ⤆

Either `pass_energy` or `drift_energy` must be supplied. `drift_energy ...

Either pass_energy or drift_energy must be supplied. drift_energy should be used if a TOF is used in the energy dispersive part of the electron analyzer.

energy_scan_mode: (recommended) NX_CHAR ⤆

entrance_slit: (optional) NXaperture ⤆

Size, position and shape of the entrance slit in dispersive analyzers. ...

Size, position and shape of the entrance slit in dispersive analyzers.

To add additional or other slits use the APERTURE group of NXenergydispersion.

exit_slit: (optional) NXaperture ⤆

Size, position and shape of the exit slit in dispersive analyzers. ...

Size, position and shape of the exit slit in dispersive analyzers.

To add additional or other slits use the APERTURE group of NXenergydispersion.

device_information: (recommended) NXfabrication ⤆

vendor: (recommended) NX_CHAR ⤆

model: (recommended) NX_CHAR ⤆

identifier: (recommended) NXidentifier ⤆

DETECTOR: (required) NXdetector ⤆

amplifier_type: (recommended) NX_CHAR ⤆

Type of electron amplifier in the first amplification step. ...

Type of electron amplifier in the first amplification step.

Any of these values: MCP | channeltron

detector_type: (recommended) NX_CHAR ⤆

Description of the detector type. ...

Description of the detector type.

Any of these values:

  • DLD

  • Phosphor+CCD

  • Phosphor+CMOS

  • ECMOS

  • Anode

  • Multi-anode

device_information: (recommended) NXfabrication ⤆

vendor: (recommended) NX_CHAR ⤆

model: (recommended) NX_CHAR ⤆

identifier: (recommended) NXidentifier ⤆

raw_data: (recommended) NXdata ⤆

Contains the raw data collected by the detector before calibration. ...

Contains the raw data collected by the detector before calibration. The data which is considered raw might change from experiment to experiment due to hardware pre-processing of the data. This group ideally collects the data with the lowest level of processing possible.

Fields should be named according to the following convention:

  • pixel_x: Detector pixel in x direction.

  • pixel_y: Detector pixel in y direction.

  • energy: (Un)calibrated energy (kinetic or binding energy). Unit category: NX_ENERGY (e.g., eV).

  • kx: (Un)calibrated x axis in k-space. Unit category: NX_ANY (e.g., 1/Angström).

  • ky: (Un)calibrated y axis in k-space. Unit category: NX_ANY (1/Angström).

  • kz: (Un)calibrated z axis in k-space. Unit category: NX_ANY (1/Angström).

  • angular0: Fast-axis angular coordinate (or second slow axis if angularly integrated). Unit category: NX_ANGLE

  • angular1: Slow-axis angular coordinate (or second fast axis if simultaneously dispersed in 2 dimensions) Unit category: NX_ANGLE

  • spatial0: Fast-axis spatial coordinate (or second slow axis if spatially integrated) Unit category: NX_LENGTH

  • spatial1: Slow-axis spatial coordinate (or second fast axis if simultaneously dispersed in 2 dimensions) Unit category: NX_LENGTH

  • delay: Calibrated delay time. Unit category: NX_TIME (s).

  • polarization_angle: Linear polarization angle of the incoming or outgoing beam. Unit category: NX_ANGLE (° or rad)

  • ellipticity: Ellipticity of the incoming or outgoing beam. Unit category: NX_ANGLE (° or rad)

  • time_of_flight: Total time of flight. Unit category: NX_TIME_OF_FLIGHT

  • time_of_flight_adc: Time-of-flight values, analog-to-digital converted.

  • external_AXIS: Describes an axis which is coming from outside the detectors scope.

Note that this list is a glossary with explicitly named axis names, which is only intended to cover the most common measurement axes and is therefore not complete. It is possible to add axes with other names at any time.

@signal: (required) NX_CHAR ⤆

Obligatory value: raw

raw: (required) NX_NUMBER ⤆

Raw data before calibration.

MANIPULATOR: (optional) NXmanipulator

Manipulator for positioning of the sample.

temperature_sensor: (recommended) NXsensor ⤆

name: (recommended) NX_CHAR ⤆

measurement: (required) NX_CHAR ⤆

Obligatory value: temperature

type: (optional) NX_CHAR ⤆

value: (required) NX_FLOAT ⤆

sample_heater: (optional) NXactuator ⤆

name: (recommended) NX_CHAR ⤆

physical_quantity: (required) NX_CHAR ⤆

Obligatory value: temperature

type: (optional) NX_CHAR ⤆

heater_power: (required) NX_FLOAT ⤆

PID: (recommended) NXpid ⤆

setpoint: (recommended) NX_FLOAT ⤆

cryostat: (optional) NXactuator ⤆

name: (recommended) NX_CHAR ⤆

physical_quantity: (required) NX_CHAR ⤆

Obligatory value: temperature

type: (optional) NX_CHAR ⤆

PID: (required) NXpid ⤆

setpoint: (recommended) NX_FLOAT ⤆

drain_current_amperemeter: (optional) NXsensor ⤆

name: (recommended) NX_CHAR ⤆

measurement: (required) NX_CHAR ⤆

Obligatory value: current

type: (optional) NX_CHAR ⤆

value: (required) NX_FLOAT ⤆

sample_bias_voltmeter: (recommended) NXsensor ⤆

name: (recommended) NX_CHAR ⤆

measurement: (required) NX_CHAR ⤆

Obligatory value: voltage

type: (optional) NX_CHAR ⤆

value: (required) NX_FLOAT ⤆

sample_bias_potentiostat: (recommended) NXactuator ⤆

name: (recommended) NX_CHAR ⤆

physical_quantity: (required) NX_CHAR ⤆

Obligatory value: voltage

type: (optional) NX_CHAR ⤆

PID: (recommended) NXpid ⤆

setpoint: (recommended) NX_FLOAT ⤆

device_information: (recommended) NXfabrication ⤆

vendor: (recommended) NX_CHAR ⤆

model: (recommended) NX_CHAR ⤆

identifier: (recommended) NXidentifier ⤆

pressure_gauge: (recommended) NXsensor ⤆

Device to measure the gas pressure in the instrument.

name: (recommended) NX_CHAR ⤆

measurement: (required) NX_CHAR ⤆

Obligatory value: pressure

type: (optional) NX_CHAR ⤆

value: (required) NX_FLOAT {units=NX_PRESSURE} ⤆

In case of a single or averaged gas pressure measurement, this is the sc ...

In case of a single or averaged gas pressure measurement, this is the scalar gas pressure. It can also be an 1D array of measured pressures (without time stamps).

value_log: (optional) NXlog ⤆

value: (required) NX_NUMBER {units=NX_PRESSURE} ⤆

In the case of an experiment in which the gas pressure changes and is ...

In the case of an experiment in which the gas pressure changes and is recorded, this is an array of length m of gas pressures.

flood_gun: (optional) NXactuator ⤆

Device to bring low-energy electrons to the sample for charge neutralization

name: (recommended) NX_CHAR ⤆

physical_quantity: (required) NX_CHAR ⤆

Obligatory value: current

type: (optional) NX_CHAR ⤆

current: (recommended) NX_FLOAT {units=NX_CURRENT} ⤆

In case of a fixed or averaged electron current, this is the scalar curr ...

In case of a fixed or averaged electron current, this is the scalar current. It can also be an 1D array of output current (without time stamps).

current_log: (optional) NXlog ⤆

value: (required) NX_NUMBER {units=NX_CURRENT} ⤆

In the case of an experiment in which the electron current is changed ...

In the case of an experiment in which the electron current is changed and recorded with time stamps, this is an array of length m of current setpoints.

history: (optional) NXhistory ⤆

A set of activities that occurred to the instrument prior to/during the ph ...

A set of activities that occurred to the instrument prior to/during the photoemission experiment, including any activities performed on the individual instrument parts. This group can be used to describe the preparation of the instrument prior to the experiment, e.g. the cleaning procedure for a spin filter crystal.

PROCESS_MPES: (recommended) NXprocess_mpes

Document an event of data processing, reconstruction, or analysis for this d ...

Document an event of data processing, reconstruction, or analysis for this data. The appropriate axis calibrations for a given experiment should be described using one or more of the following NXcalibrations. The individual calibrations for a given AXISNAME in data should be called AXISNAME_calibration.

energy_calibration: (optional) NXcalibration ⤆

calibrated_axis: (recommended) NX_FLOAT ⤆

kN_calibration: (optional) NXcalibration ⤆

calibrated_axis: (recommended) NX_FLOAT ⤆

angularN_calibration: (optional) NXcalibration ⤆

calibrated_axis: (recommended) NX_FLOAT ⤆

spatialN_calibration: (optional) NXcalibration ⤆

calibrated_axis: (recommended) NX_FLOAT ⤆

delay_calibration: (optional) NXcalibration ⤆

calibrated_axis: (recommended) NX_FLOAT ⤆

polarization_angle_calibration: (optional) NXcalibration ⤆

calibrated_axis: (recommended) NX_FLOAT ⤆

ellipticity_calibration: (optional) NXcalibration ⤆

calibrated_axis: (recommended) NX_FLOAT ⤆

energy_referencing: (optional) NXcalibration ⤆

reference_peak: (required) NX_CHAR ⤆

binding_energy: (recommended) NX_FLOAT {units=NX_ENERGY} ⤆

offset: (recommended) NX_FLOAT {units=NX_ENERGY} ⤆

calibrated_axis: (recommended) NX_FLOAT {units=NX_ENERGY} ⤆

level: (recommended) NXelectron_level ⤆

transmission_correction: (optional) NXcalibration ⤆

transmission_function: (recommended) NXdata ⤆

@signal: (required) NX_CHAR ⤆

@axes: (required) NX_CHAR ⤆

kinetic_energy: (required) NX_FLOAT (Rank: 1, Dimensions: [n_transmission_function]) {units=NX_ENERGY} ⤆

Kinetic energy values

relative_intensity: (required) NX_FLOAT (Rank: 1, Dimensions: [n_transmission_function]) {units=NX_UNITLESS} ⤆

Relative transmission efficiency for the given kinetic energies

SAMPLE: (required) NXsample ⤆

name: (required) NX_CHAR ⤆

atom_types: (recommended) NX_CHAR

List of comma-separated elements from the periodic table ...

List of comma-separated elements from the periodic table that are contained in the sample. If the sample substance has multiple components, all elements from each component must be included in atom_types.

physical_form: (recommended) NX_CHAR ⤆

situation: (recommended) NX_CHAR ⤆

Any of these values:

  • vacuum

  • inert atmosphere

  • oxidising atmosphere

  • reducing atmosphere

identifier: (recommended) NXidentifier ⤆

SUBSTANCE: (recommended) NXsubstance ⤆

For samples containing a single pure substance. For mixtures use the ...

For samples containing a single pure substance. For mixtures use the NXsample_component_set and NXsample_component group in NXsample instead.

molecular_formula_hill: (recommended) NX_CHAR ⤆

The chemical formula of the sample (using CIF conventions).

history: (recommended) NXhistory ⤆

A set of activities that occurred to the sample prior to/during photoemiss ...

A set of activities that occurred to the sample prior to/during photoemission experiment.

sample_preparation: (recommended) NXphysical_process ⤆

Details about the sample preparation for the photoemission experiment (e ...

Details about the sample preparation for the photoemission experiment (e.g. UHV cleaving, in-situ growth, sputtering/annealing, etc.).

start_time: (required) NX_DATE_TIME ⤆

end_time: (recommended) NX_DATE_TIME ⤆

method: (recommended) NX_CHAR ⤆

Details about the method of sample preparation before the photoemissio ...

Details about the method of sample preparation before the photoemission experiment.

temperature_env: (recommended) NXenvironment ⤆

Sample temperature (either controlled or just measured) and actuators/sens ...

Sample temperature (either controlled or just measured) and actuators/sensors controlling/measuring it.

value: (optional) NX_FLOAT {units=NX_TEMPERATURE} ⤆

This is to be used if there is no actuator/sensor that controls/measures ...

This is to be used if there is no actuator/sensor that controls/measures the temperature.

An example would be a room temperature experiment where the temperature is not actively measured, but rather estimated.

Note that this method for recording the temperature is not advised, but using NXsensor and NXactuator is strongly recommended instead.

temperature_sensor: (recommended) NXsensor ⤆

Temperature sensor measuring the sample temperature. ...

Temperature sensor measuring the sample temperature.

In most cases, this can be a link to /entry/instrument/manipulator/temperature_sensor if a manipulator is present in the instrument.

sample_heater: (optional) NXactuator ⤆

Device to heat the sample. ...

Device to heat the sample.

In most cases, this can be a link to /entry/instrument/manipulator/sample_heater if a manipulator is present in the instrument.

cryostat: (optional) NXactuator ⤆

Cryostat for cooling the sample. ...

Cryostat for cooling the sample.

In most cases, this can be a link to /entry/instrument/manipulator/cryostat if a manipulator is present in the instrument.

gas_pressure_env: (recommended) NXenvironment ⤆

Gas pressure surrounding the sample and actuators/sensors controlling/meas ...

Gas pressure surrounding the sample and actuators/sensors controlling/measuring it.

value: (optional) NX_FLOAT {units=NX_PRESSURE} ⤆

This is to be used if there is no actuator/sensor that controls/measures ...

This is to be used if there is no actuator/sensor that controls/measures the gas pressure around the sample. An example would be a UHV experiment where the gas pressure is not monitored.

Note that this method for recording the gas pressure is not advised, but using NXsensor and NXactuator is strongly recommended instead.

pressure_gauge: (recommended) NXsensor ⤆

Gauge measuring the gas pressure. ...

Gauge measuring the gas pressure.

In most cases, this can be a link to /entry/instrument/pressure_gauge or to another NXsensor measuring gas pressure (typically, the gauge in closest proximity to the sample) if such a pressure gauge is present in the instrument.

bias_env: (recommended) NXenvironment ⤆

Bias of the sample with respect to analyser ground and actuators/sensors ...

Bias of the sample with respect to analyser ground and actuators/sensors controlling/measuring it.

This concept is related to term 8.41 of the ISO 18115-1:2023 standard.

value: (optional) NX_FLOAT {units=NX_VOLTAGE} ⤆

This is to be used if there is no actuator/sensor that controls/measures ...

This is to be used if there is no actuator/sensor that controls/measures the bias.

Note that this method for recording the bias is not advised, but using NXsensor and NXactuator is strongly recommended instead.

voltmeter: (recommended) NXsensor ⤆

Sensor measuring the applied voltage. ...

Sensor measuring the applied voltage.

In most cases, this can be a link to /entry/instrument/manipulator/sample_bias_voltmeter if a manipulator is present in the instrument.

potentiostat: (optional) NXactuator ⤆

Actuator applying a voltage to sample and sample holder. ...

Actuator applying a voltage to sample and sample holder.

In most cases, this can be a link to /entry/instrument/manipulator/sample_bias_potentiostat if a manipulator is present in the instrument.

drain_current_env: (optional) NXenvironment ⤆

Drain current of the sample and sample holder.

value: (optional) NX_FLOAT {units=NX_CURRENT} ⤆

This is to be used if there is no actuator/sensor that controls/measures ...

This is to be used if there is no actuator/sensor that controls/measures the drain current.

Note that this method for recording the drain current is not advised, but using NXsensor and NXactuator is strongly recommended instead.

amperemeter: (recommended) NXsensor ⤆

Amperemeter measuring the drain current of the sample and sample holder. ...

Amperemeter measuring the drain current of the sample and sample holder.

In most cases, this can be a link to /entry/instrument/manipulator/drain_current_amperemeter if a manipulator is present in the instrument.

flood_gun_current_env: (optional) NXenvironment ⤆

Current of low-energy electrons to the sample (for charge neutralization) ...

Current of low-energy electrons to the sample (for charge neutralization) and actuators/sensors controlling/measuring it.

flood_gun: (recommended) NXactuator ⤆

Flood gun creating a current of low-energy electrons. ...

Flood gun creating a current of low-energy electrons.

In most cases this can be a link to /entry/instrument/flood_gun if a flood_gun is present in the instrument.

value: (optional) NX_FLOAT {units=NX_CURRENT} ⤆

This is to be used if there is no actuator/sensor that controls/measur ...

This is to be used if there is no actuator/sensor that controls/measures the drain_current.

Note that this method for recording the flood gun current is not advised, but using NXsensor and NXactuator is strongly recommended instead.

data: (required) NXdata ⤆

The default NXdata group containing a view on the measured data. ...

The default NXdata group containing a view on the measured data. This NXdata group contains a collection of the main relevant fields (axes). If you want to provide additional views on your data, you can additionally use the generic NXdata group of NXentry.

In NXmpes, it is recommended to provide an energy axis.

Fields should be named according to the following convention:

  • energy: Calibrated energy (kinetic or binding energy). Unit category: NX_ENERGY (e.g., eV).

  • kx: Calibrated x axis in k-space. Unit category: NX_ANY (e.g., 1/Angström).

  • ky: Calibrated y axis in k-space. Unit category: NX_ANY (1/Angström).

  • kz: Calibrated z axis in k-space. Unit category: NX_ANY (1/Angström).

  • angular0: Fast-axis angular coordinate (or second slow axis if angularly integrated). Unit category: NX_ANGLE

  • angular1: Slow-axis angular coordinate (or second fast axis if simultaneously dispersed in 2 dimensions) Unit category: NX_ANGLE

  • spatial0: Fast-axis spatial coordinate (or second slow axis if spatially integrated) Unit category: NX_LENGTH

  • spatial1: Slow-axis spatial coordinate (or second fast axis if simultaneously dispersed in 2 dimensions) Unit category: NX_LENGTH

  • delay: Calibrated delay time. Unit category: NX_TIME (s).

  • polarization_angle: Linear polarization angle of the incoming or outgoing beam. This could be a link to /entry/instrument/beam/incident_polarization_angle or /entry/instrument/beam/final_polarization_angle if they exist. Unit category: NX_ANGLE (° or rad)

  • ellipticity: Ellipticity of the incoming or outgoing beam. Could be a link to /entry/instrument/beam/incident_ellipticity or /entry/instrument/beam/final_ellipticity if they exist. Unit category: NX_ANGLE (° or rad)

Note that this list is a glossary with explicitly named axis names, which is only intended to cover the most common measurement axes and is therefore not complete. It is possible to add axes with other names at any time.

@signal: (required) NX_CHAR ⤆

Obligatory value: data

@energy_indices: (recommended) NX_CHAR

data: (required) NX_NUMBER {units=NX_ANY} ⤆

Represents a measure of one- or more-dimensional photoemission counts, whe ...

Represents a measure of one- or more-dimensional photoemission counts, where the varied axis may be for example energy, momentum, spatial coordinate, pump-probe delay, spin index, temperature, etc. The axes traces should be linked to the actual encoder position in NXinstrument or calibrated axes in NXprocess.

energy: (recommended) NX_NUMBER {units=NX_ENERGY} ⤆

Calibrated energy axis. ...

Calibrated energy axis.

Could be linked from the respective ‘@reference’ field.

@type: (required) NX_CHAR ⤆

The energy can be either stored as kinetic or as binding energy. ...

The energy can be either stored as kinetic or as binding energy.

Any of these values:

  • kinetic: Calibrated kinetic energy axis. In case the kinetic energy axis is referenced to the Fermi level \(E_F\) (e.g., in entry/process/energy_referencing), kinetic energies \(E\) are provided as \(E-E_F\). This concept is related to term 3.35 of the ISO 18115-1:2023 standard.

  • binding: Calibrated binding energy axis. This concept is related to term 12.16 of the ISO 18115-1:2023 standard.

@reference: (recommended) NX_CHAR ⤆

The energy can be dispersed according to different strategies. ``@refere ...

The energy can be dispersed according to different strategies. @reference points to the path of a field defining the calibrated axis which the energy axis refers.

For example:

@reference: ‘entry/process/energy_calibration/calibrated_axis’

Hypertext Anchors

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

NXDL Source:

https://github.com/FAIRmat-NFDI/nexus_definitions/tree/fairmat/contributed_definitions/NXmpes.nxdl.xml