WDS Flashcards
WDS is less common on SEM systems than EDS, even though WDS has a……
Greater sensitivity and resolution than EDS.
Beam size?
1-2 micrometers in diameter.
What is WDS?
Spectrometry using a single crystal that can absorb incoming X-rays, become ionised and emit electrons that are detected as a current.
How is WDS similar to EDS?
Both have a single crystal that can absorb incoming X-rays, become ionised and emit electrons that are detected as a current.
How does WDS differ from EDS?
WDS crystals have specific internal crystal dimensions that only absorb X-rays that are emitted from the sample at a specific angle. Therefore each WDS crystal is unique to a single element.
What type of analysis is WDS?
Quantitive analysis
The use of WDS on an electron microprobe (EMPA).
Several WDS detectors can be used in a single EMPA, which allows the detection of multiple elements down to 200ppb.
An EMPA is similar to SEM as it bombards the sample with multiple electrons, however it differs from SEM because….
It cannot be used on solid chips, unlike SEM.
An electron microprobe can provide info about….
Spacial distribution of analytes.
