1 Concept scheme: XAS detection modes
Vocabulary last modified: 2026-10-27
subtitle: Detection methods used to observe sample absorption in an XAS measurement. Value list for the CDIF XAS concept ‘xasmeasurementmode’. This list is the union of the upstream NeXus NXxas mode enumeration and the per-mode application definitions in the XAS community fork: the fork adds HERFD and splits total from partial fluorescence yield, but drops Auger electron yield.
Namespace: https://w3id.org/cdif/xas/XAS_DetectionModes
History
Concepts
1.1 Transmission
- Child of:
xasmeasurementmode - The absorption coefficient is obtained from the Beer-Lambert law, mu(E)t = -ln(I/I0), where I is the transmitted and I0 the incident beam intensity.
- Alternate labels: trans
- Concept URI: https://w3id.org/cdif/xas/detectionmode/transmission
1.2 Total electron yield
- Child of:
xasmeasurementmode - The spectrum is measured by collecting all secondary electrons emitted from the sample surface; the drain current is proportional to the absorption coefficient.
- Alternate labels: TEY
- Concept URI: https://w3id.org/cdif/xas/detectionmode/totalelectronyield
1.3 Partial electron yield
- Child of:
xasmeasurementmode - The spectrum is measured by collecting electrons above a kinetic energy threshold, using a retarding voltage to discriminate against low-energy secondary electrons.
- Alternate labels: PEY
- Concept URI: https://w3id.org/cdif/xas/detectionmode/partialelectronyield
1.4 Auger electron yield
- Child of:
xasmeasurementmode - The spectrum is measured by collecting Auger electrons of a selected kinetic energy.
- Alternate labels: AEY
- Concept URI: https://w3id.org/cdif/xas/detectionmode/augerelectronyield
1.5 Total fluorescence yield
- Child of:
xasmeasurementmode - The absorption coefficient is proportional to the ratio of total fluorescence intensity to incident beam intensity.
- Alternate labels: TFY
- Concept URI: https://w3id.org/cdif/xas/detectionmode/totalfluorescenceyield
1.6 Partial fluorescence yield
- Child of:
xasmeasurementmode - The absorption coefficient is obtained from fluorescence intensity measured over a selected emission-energy window or detector channels.
- Alternate labels: PFY
- Concept URI: https://w3id.org/cdif/xas/detectionmode/partialfluorescenceyield
1.7 High energy resolution fluorescence detected
- Child of:
xasmeasurementmode - The spectrum is measured with crystal analyzers selecting a narrow emission energy, giving sharper spectral features than conventional fluorescence detection.
- Alternate labels: HERFD
- Concept URI: https://w3id.org/cdif/xas/detectionmode/herfd