Scanning Electron Microscopy and X-Ray Microanalysis

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25

. Fig. 25.3 Selection of VPSEM
gas parameters in DTSA-II for
simulation
. Table 25.1 Portion of the electron scattering table for VPSEM simulation. Note the unscattered fraction of the 20 keV beam, 0.701
(100 Pa, 5-mm gas path length, oxygen). The full table extends to 1000 μm

Ring Inner radius,

μm

Outer radius,

μm

Ring area,

μm^2

Electron count Electron

fraction

Cumulative, %

Undeflected – – – 701 0.701 –

1 0.0 2.5 19.6 755 0.755 75.5

2 2.5 5.0 58.9 23 0.023 77.8

3 5.0 7.5 98.2 11 0.011 78.9

4 7.5 10.0 137.4 10 0.010 79. 9

5 10.0 12.5 176.7 7 0.007 80.6

6 12.5 15.0 216.0 6 0.006 81.2

7 15.0 17.5 255.3 9 0.009 82.1

8 17.5 20.0 294.5 10 0.010 83.1

9 20.0 22.5 333.8 4 0.004 83.5

10 22.5 25.0 373.1 3 i 0.003 83.8

11 25.0 27.5 412.3 6 0.006 84.4

12 27.5 30.0 451.6 4 0.004 84.8

13 30.0 32.5 490.9 6 0.006 85.4

14 32.5 35.0 530.1 2 0.002 85.6

15 35.0 37.5 569.4 2 0.002 85.8

16 37.5 40.0 608.7 3 0.003 86.1

17 40.0 42.5 648.0 4 0.004 86.5

Chapter 25 · Attempting Electron-Excited X-Ray Microanalysis in the Variable Pressure Scanning Electron Microscope (VPSEM)