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).

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.