2.3.3.3.3. Photoemission & core-level spectroscopy

Introduction

Set of data storage objects to describe photoemission experiments including x-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), hard x-ray photoelectron spectroscopy (HAXPES), angle-resolved photoemission spectroscopy (ARPES), two-photon photoemission (2PPE) and photoemission electron microscopy (PEEM). Also includes descriptors for advanced specializations, such as spin-resolution, time resolution, near-ambient pressure conditions, dichroism etc.

Application Definitions

NXmpes:

A general application definition with minimalistic metadata requirements, apt to describe all photemission experiments.

NXmpes_arpes:

An application definition for angle-resolved photoemission spectroscopy (ARPES) experiments.

NXxps:

An application definition for X-ray/UV photoelectron spectroscopy (XPS/UPS) experiments.

Base Classes

NXelectronanalyzer:

A base class to describe electron kinetic energy analyzers. Contains the collective characteristics of the instrument such as energy resolution, and includes the following classes:

NXcollectioncolumn:

Base class to describe the set of electronic lenses in the electron collection column (standard, PEEM, momentum-microscope, etc.).

NXenergydispersion:

Base class to describe the energy dispersion system (hemispherical, time-of-flight, etc.).

NXspindispersion:

Base class to describe spin filters in photoemission experiments.

NXelectron_detector:

Specialization of NXdetector to describe electron detectors used in photoemission experiments.

Four base classes (which are subclasses of NXprocess) to describe data (post-)processing:

NXcalibration:

Base class to describe the 1D calibration of an axis, with a function mapping a raw data scale to a calibrated scale with the same number of points.

NXdistortion:

Base class to describe the 2D distortion correction of an axis, with a matrix mapping a raw data image to a undistorted image.

NXregistration:

Base class to describe the rigid transformations that are applied to an image.

NXfit:

Base class to describe a fit procedure (e.g., peak fitting in XPS). This comes with its own set of base classes:

NXfit_function:

Base class to describe a fit function that is used to fit data to any functional form.

NXpeak:

Base class to describe a peak, its functional form, and support values (i.e., the discretization (points) at which the function has been evaluated).

NXfit_background:

Description of the background for an NXfit model.

Common Base Classes

There are three related base classes that are common to other techniques:

NXmanipulator:

A base class to describe the complex manipulators used in experiments, often with > 4 degrees of freedom, cryogenic cooling, and other advanced features.

NXlens_em:

A class to describe all types of lenses. Includes electrostatic lenses for electron energy analysers.

NXdeflector

A class to describe all kinds of deflectors, including electrostatic and magnetostatic deflectors for electron energy analysers.