Scanning Electron Microscopy and X-Ray Microanalysis

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16


EDS black box
Input:
X-ray photon

Output:
an estimate of
photon energy

Photon energy

Number of photon

s

Repeated measurements of the same
photon energy produce a range of
values: this is the spectrometer
resolution effect.

True Mn K-L2,3 X-ray energy width ~ 7 eV

. Fig. 16.2 “Black box” repre-
sentation of the EDS detection
and histogram binning process


Mn
E 0 = 20 keV

Photon energy (keV)

Photon energy (keV)

Counts

Co

unts

Mn_20keV

Mn_20keV

100 000

80 000

60 000

40 000

20 000

C K
-L2+3

Mn
L2-M1+3-M1

Mn
L2-M4+N1, Mn

L3-M4+5

Mn
L2-M2+3

Mn
K-L2+3

Mn
K-M2+3

Mn
K-M2+3

Mn
K-L2

Si K
-L2+3Si K
-M2+3

Mn
esc

0
0246810

100 000

80 000

60 000

40 000

20 000

0
5 000 5 200 5 400 5 600 5 800 6 000 6 200 6 400 6 600 6 800 7 000

Mn
K-L3

. Fig. 16.3 SDD-EDS spectrum of Mn with E 0 = 20 keV and a time constant that produces a resolution of FWHM = 129 eV at Mn K-L2,3


Chapter 16 · Energy Dispersive X-ray Spectrometry: Physical Principles and User-Selected Parameters
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