212
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