3.3.3.104. NXxas_pey

Status:

application definition (contribution), extends NXxas

Description:

In partial electron yield (PEY), the XAS spectrum is measured by ...

In partial electron yield (PEY), the XAS spectrum is measured by collecting electrons above a certain kinetic energy threshold. A retarding voltage (bias) is applied to discriminate against low-energy secondary electrons, selecting only higher-energy Auger or photoelectrons:

\[\mu(E) \propto I_{ey}/I_0\]

By selecting a specific energy range, PEY can enhance the surface sensitivity and selectivity compared to total electron yield.

The top-level intensity field stores the ratio \(I_{ey}/I_0\). When the raw detector data and processing steps are available, they can be stored in the optional NXinstrument and NXprocess groups, enabling full reproducibility of the data reduction.

Symbols:

No symbol table

Groups cited:

NXdetector, NXentry, NXinstrument, NXprocess

Structure:

ENTRY: (required) NXentry ⤆

definition: (required) NX_CHAR ⤆

Official NeXus NXDL schema to which this file conforms. ...

Official NeXus NXDL schema to which this file conforms.

Obligatory value: NXxas_pey

intensity: (required) NX_FLOAT (Rank: 1, Dimensions: [nEnergy]) {units=NX_ANY} ⤆

The absorption coefficient :math:`\mu(E) \propto I_{ey}/I_0`, ...

The absorption coefficient \(\mu(E) \propto I_{ey}/I_0\), where \(I_{ey}\) is the partial electron yield signal above the retarding voltage threshold.

INSTRUMENT: (optional) NXinstrument ⤆

i0: (required) NXdetector ⤆

Detector measuring the incident beam intensity ...

Detector measuring the incident beam intensity \(I_0\).

data: (required) NX_NUMBER (Rank: 1, Dimensions: [nEnergy]) ⤆

iey: (required) NXdetector ⤆

Detector measuring the partial electron yield ...

Detector measuring the partial electron yield \(I_{ey}\).

data: (required) NX_NUMBER (Rank: 1, Dimensions: [nEnergy]) ⤆

retarding_voltage: (optional) NX_FLOAT {units=NX_VOLTAGE}

The retarding voltage (bias) applied to select ...

The retarding voltage (bias) applied to select electrons above a kinetic energy threshold.

PROCESS: (optional) NXprocess ⤆

Description of how :ref:`intensity ...

Description of how intensity was obtained from the raw detector data (i0, iey).

program: (optional) NX_CHAR ⤆

Name of the program used for processing.

version: (optional) NX_CHAR ⤆

Version of the program used for processing.

date: (optional) NX_DATE_TIME ⤆

Date and time of processing.

Hypertext Anchors

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

NXDL Source:

https://github.com/nexusformat/definitions/blob/main/contributed_definitions/NXxas_pey.nxdl.xml