Scanning Electron Microscopy and X-Ray Microanalysis

352

21

10 mm 12 mm 14 mm

0102030405060708090100

16 mm 18 mm 20 mm

1 mm

0

200

400

600

800

1000

1200

810121416182022

Working distance (mm)

Al counts/pixel

Al machined surface

. Fig. 21.11 X-ray mapping to
determine the acceptance volume
of the collimator. A series of Al
X-ray maps of an aluminum SEM
stub at different working
distances is shown; the inset
graph shows the intensity at the
center of each map as a function
of working distance

EDS

detector

window

Collimator &

electron trap

Final

lens

Chamber

wall

BSE

BSE

Remote X-rays

Several mm

Green =

Extent of

specimen

X-ray sources

NOT excluded

by collimator

Specimen X-rays

. Fig. 21.10 True extent of
acceptance area of EDS
constructed by looking out
through the collimator

Chapter 21 · Trace Analysis by SEM/EDS