NXpulser_apm

Status:

base class, extends NXobject

Description:

Metadata for laser- and/or voltage-pulsing in atom probe microscopy.

Symbols:

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

n_ions: Total number of ions collected.

Groups cited:

NXbeam, NXcollection, NXfabrication, NXsource, NXtransformations

Structure:

pulse_mode: (optional) NX_CHAR

How is field evaporation physically triggered.

Any of these values: laser | voltage | laser_and_voltage

pulse_frequency: (optional) NX_FLOAT {units=NX_FREQUENCY}

Frequency with which the high voltage or laser pulser fires.

pulse_fraction: (optional) NX_FLOAT {units=NX_DIMENSIONLESS}

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

pulsed_voltage: (optional) NX_FLOAT (Rank: 1, Dimensions: [n_ions]) {units=NX_VOLTAGE}

In laser pulsing mode the values will be zero so the this field is recommended. However, for voltage pulsing mode it is highly recommended that users report the pulsed_voltage.

standing_voltage: (optional) NX_FLOAT (Rank: 1, Dimensions: [n_ions]) {units=NX_VOLTAGE}

Direct current voltage between the specimen and the (local electrode) in the case of local electrode atom probe (LEAP) instrument.

FABRICATION: (optional) NXfabrication

laser_gun: (optional) NXsource

Atom probe microscopes use controlled laser, voltage, or a combination of pulsing strategies to trigger the excitation and eventual field evaporation/emission of an ion during an experiment.

name: (optional) NX_CHAR

Given name/alias.

wavelength: (optional) NX_FLOAT {units=NX_WAVELENGTH}

Nominal wavelength of the laser radiation.

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.

FABRICATION: (optional) NXfabrication

TRANSFORMATIONS: (optional) NXtransformations

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. A right-handed Cartesian coordinate system, the so-called laser space, should be assumed, whose positive z-axis points into the direction of the propagating laser beam.

laser_beam: (optional) NXbeam

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

pinhole_position: (optional) NXcollection

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

spot_position: (optional) NXcollection

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

Hypertext Anchors

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

NXDL Source:

https://github.com/FAIRmat-Experimental/nexus_definitions/tree/fairmat/contributed_definitions/NXpulser_apm.nxdl.xml