Scanning Electron Microscopy and X-Ray Microanalysis

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16

Elevation angle

Objective

lens

Optimal

working

distance

C

L

Y

X

Z

Axes

ψ:

EDS detec

tor snout

Sample

. Fig. 16.11 The elevation
angle is a fixed property of the
instrument/detector

Sample

Detector

crystal

Objective

lens

C

L

W

Sample-to

-detector

distance

. Fig. 16.12 The solid angle is a
function of sample-to-detector
distance and the active detector
area

angle is illustrated in the. Fig. 16.12. Moving the detector

away from the sample is designed to decrease the solid angle

but does not change the elevation angle or the optimal work-

ing distance.

It is important to be able to maintain a reproducible solid

angle through consistent repositioning of the detector. Some

slide mechanisms are motorized. Motorized mechanisms

should define an “inserted” position and a “retracted”

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