2.3.3.1.7. NXapm_instrument

Status:

base class, extends NXinstrument

Description:

Base class for instrument-related details of a real or simulated ...

Base class for instrument-related details of a real or simulated atom probe tomograph or field-ion microscope.

For collecting data and experiments which are simulations of an atom probe microscope or a session with such instrument use the NXapm application definition and the NXapm_event_data groups it provides.

This base class implements the concept of NXapm whereby (meta)data are distinguished whether these typically change during a session, so-called dynamic, or not, so-called static metadata. This design allows to store e.g. hardware related concepts only once instead of demanding that each image or spectrum from the session needs to be stored also with the static metadata.

Symbols:

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

p: Number of pulses collected in between start_time and end_time inside a parent instance of NXapm_event_data.

Groups cited:

NXbeam, NXcomponent, NXdetector, NXfabrication, NXmanipulator, NXparameters, NXpump, NXsensor, NXsource, NXtransformations

Structure:

type: (optional) NX_CHAR

Which type of instrument. ...

Which type of instrument.

Any of these values or a custom value (if you use a custom value, also set @custom=True):

  • Inspico

  • 3DAP

  • LAWATAP

  • LEAP 3000 Si

  • LEAP 3000X Si

  • LEAP 3000 HR

  • LEAP 3000X HR

  • LEAP 4000 Si

  • LEAP 4000X Si

  • LEAP 4000 HR

  • LEAP 4000X HR

  • LEAP 5000 XS

  • LEAP 5000 XR

  • LEAP 5000 R

  • EIKOS

  • EIKOS-UV

  • LEAP 6000 XR

  • LEAP INVIZO

  • Photonic AP

  • TeraSAT

  • TAPHR

  • Modular AP

  • Titanium APT

  • Extreme UV APT

location: (optional) NX_CHAR

Location of the lab or place where the instrument is installed. Using GEOREF i ...

Location of the lab or place where the instrument is installed. Using GEOREF is preferred.

flight_path: (optional) NX_FLOAT {units=NX_LENGTH}

Nominal flight path ...

Nominal flight path

The value can be extracted from the CAnalysis.CSpatial.fFlightPath field of a CamecaRoot ROOT file.

comment: (optional) NX_CHAR

Free-text field for additional comments.

fabrication: (optional) NXfabrication ⤆

reflectron: (optional) NXcomponent

Device which reduces ToF differences of ions in ToF experiments. ...

Device which reduces ToF differences of ions in ToF experiments.

For atom probe the reflectron can be considered an energy compensation device. Such a device can be realized technically e.g. with a Poschenrieder lens.

Consult the following U.S. patents for further details:

  • 3863068 and 6740872 for the reflectron

  • 8134119 for the curved reflectron

applied: (optional) NX_BOOLEAN ⤆

Was the reflectron used?

voltage: (optional) NX_FLOAT {units=NX_VOLTAGE}

The maximum voltage applied to the reflectron, relative to system ground.

decelerate_electrode: (optional) NXcomponent

A counter electrode of the LEAP 6000 series atom probes.

local_electrode: (optional) NXcomponent

A local electrode guiding the ion flight path. ...

A local electrode guiding the ion flight path. Also called counter or extraction electrode.

voltage: (optional) NX_FLOAT {units=NX_VOLTAGE}

Acceleration voltage

aperture_type: (optional) NX_CHAR

The type of aperture used when the local_electrode has an aperture or acts a ...

The type of aperture used when the local_electrode has an aperture or acts as an aperture in addition to acting as an extraction electrode.

The local electrode is a component which combines functionalities of NXelectromagnetic_lens, NXaperture, if not even NXdeflector:

  • “n/a”, use when no aperture is present in the experiment

  • “conical”, conical aperture with a circular hole

  • “feedthrough”, an aperture where the specimen protrudes through a circular hole

  • “custom”, a user modified aperture, which is otherwise non-standard

Any of these values: n/a | conical | feedthrough | custom

ion_detector: (optional) NXdetector ⤆

Detector for taking raw time-of-flight and ion/hit impact positions data.

signal_amplitude: (optional) NX_FLOAT (Rank: 1, Dimensions: [p]) {units=NX_CURRENT}

Amplitude of the signal detected on the multi-channel plate (MCP). ...

Amplitude of the signal detected on the multi-channel plate (MCP).

This field should be used for storing the signal amplitude quantity within ATO files when the detector was an MCP.

The ATO file format is used primarily by the atom probe group of the GPM in Rouen, France.

mcp_efficiency: (optional) NX_FLOAT {units=NX_DIMENSIONLESS}

The value can be extracted from the CRunHeader.fMcpEfficiency ...

The value can be extracted from the CRunHeader.fMcpEfficiency field of a CamecaRoot RHIT file.

mesh_efficiency: (optional) NX_FLOAT {units=NX_DIMENSIONLESS}

The value can be extracted from the CRunHeader.fMeshEfficiency ...

The value can be extracted from the CRunHeader.fMeshEfficiency field of a CamecaRoot RHIT file.

pulser: (optional) NXcomponent

Laser- and/or voltage-pulsing device to trigger ion removal. ...

Laser- and/or voltage-pulsing device to trigger ion removal.

When the base class NXapm_instrument is used in the NXapm application definition, the values for the following fields:

  • pulse_frequency

  • pulse_fraction

  • pulse_voltage

  • pulse_number

  • standing_voltage

  • pulse_energy

  • incidence_vector

  • pinhole_position

  • spot_position

should be recorded in the order of, and assumed associated, with the pulse_id in an instance of NXapm_event_data.

pulse_mode: (optional) NX_CHAR

Detail whereby ion extraction is triggered methodologically. ...

Detail whereby ion extraction is triggered methodologically.

Any of these values or a custom value (if you use a custom value, also set @custom=True): laser | voltage | laser_and_voltage

pulse_frequency: (optional) NX_FLOAT {units=NX_FREQUENCY}

Frequency with which the pulser fire(s).

pulse_fraction: (optional) NX_FLOAT {units=NX_DIMENSIONLESS}

Fraction of the pulse_voltage that is applied in addition ...

Fraction of the pulse_voltage that is applied in addition to the standing_voltage at peak voltage of a pulse.

If a standing voltage is applied, this gives nominal pulse fraction (as a function of standing voltage). Otherwise, this field should not be present.

pulse_voltage: (optional) NX_FLOAT {units=NX_VOLTAGE}

Pulsed voltage, in laser pulsing mode this field can be omitted.

pulse_number: (optional) NX_UINT {units=NX_UNITLESS}

Absolute number of pulses starting from the beginning of the experiment.

standing_voltage: (optional) NX_FLOAT {units=NX_VOLTAGE}

Direct current voltage between the specimen and the (local electrode) in ...

Direct current voltage between the specimen and the (local electrode) in the case of local electrode atom probe (LEAP) instrument. Otherwise, the standing voltage applied to the sample, relative to system ground.

fabrication: (optional) NXfabrication ⤆

sourceID: (optional) NXsource

Group to store details about components that enable laser pulsing strategies ...

Group to store details about components that enable laser pulsing strategies.

When multiple sources are available, these should be named source1, source2; the LEAP 6000 series instruments have two sources. The majority of instruments still has one source. In this case the variable part “ID” can be omitted. Consequently the group should be named “source” when writing instance data.

Atom probe microscopes use controlled laser, voltage, or a combination of pulsing strategies to trigger ion extraction via exciting and eventual field evaporation field emission of ion at the specimen surface.

wavelength: (optional) NX_FLOAT {units=NX_WAVELENGTH} ⤆

The wavelength of the radiation emitted by the source.

power: (optional) NX_FLOAT {units=NX_POWER} ⤆

Nominal power of the laser source while illuminating the specimen.

pulse_energy: (optional) NX_FLOAT {units=NX_ENERGY} ⤆

Average energy of the laser at peak of each pulse.

@logged_against: (optional) NX_CHAR

Path to pulse_id

beamID: (optional) NXbeam

Details about specific positions along the laser beam ...

Details about specific positions along the laser beam which illuminates the (atom probe) specimen.

incidence_vector: (optional) NX_NUMBER {units=NX_LENGTH}

Track time-dependent settings over the course of the measurement ...

Track time-dependent settings over the course of the measurement how the laser beam shines on the specimen, i.e. the mean vector is parallel to the laser propagation direction.

pinhole_position: (optional) NX_NUMBER {units=NX_LENGTH}

Track time-dependent settings over the course of the measurement ...

Track time-dependent settings over the course of the measurement where the laser beam exits the focusing optics.

spot_position: (optional) NX_NUMBER {units=NX_LENGTH}

Track time-dependent settings over the course of the ...

Track time-dependent settings over the course of the measurement where the laser hits the specimen.

TRANSFORMATIONS: (optional) NXtransformations ⤆

Affine transformations which describe the geometry how the ...

Affine transformations which describe the geometry how the laser focusing optics/pinhole-attached coordinate system is defined, how it has to be transformed so that it aligns with the specimen coordinate system.

stage: (optional) NXmanipulator

temperature_sensor: (optional) NXsensor ⤆

value: (optional) NX_FLOAT ⤆

The value can be extracted from the CRunHeader.CAnalysis.fSpecimenTemperat ...

The value can be extracted from the CRunHeader.CAnalysis.fSpecimenTemperature field of a CamecaRoot RHIT file.

analysis_chamber: (optional) NXcomponent

flight_path: (optional) NX_FLOAT {units=NX_LENGTH}

The space inside the atom probe along which ions pass nominally ...

The space inside the atom probe along which ions pass nominally when they leave the specimen and travel to the detector.

pressure_sensor: (optional) NXsensor

measurement: (optional) NX_CHAR ⤆

Obligatory value: pressure

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

The value can be extracted from the CRunHeader.CLasHeader.fAnalysisPressur ...

The value can be extracted from the CRunHeader.CLasHeader.fAnalysisPressure field of a CamecaRoot RHIT file.

buffer_chamber: (optional) NXcomponent

load_lock_chamber: (optional) NXcomponent

getter_pump: (optional) NXpump

roughening_pump: (optional) NXpump

turbomolecular_pump: (optional) NXpump

control: (optional) NXparameters ⤆

Relevant quantities during a measurement with a LEAP system as were ...

Relevant quantities during a measurement with a LEAP system as were suggested by T. Blum et al..

evaporation_control: (optional) NX_CHAR

Parameter that defines the rules and control loops whereby the pulser and ...

Parameter that defines the rules and control loops whereby the pulser and other components of the instrument are controlled during evaporation.

target_detection_rate: (optional) NX_NUMBER {units=NX_ANY}

Parameter that assure maintenance of a significant yet not too high ...

Parameter that assure maintenance of a significant yet not too high ion influx on the detector to avoid detection losses.

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/base_classes/NXapm_instrument.nxdl.xml