FEI Quanta FEG 250, Руководство пользователя

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System Options: Heating Stage 1000 °C / Heating Stage 1500 °C
9-47
done by simply rotating the detector so that one of the gaps in the ring
faces the EDX detector. In the following photo, note that the bars on
the collection ring are oriented so that the path from the EDX detector
to the GSED is clear.
Also note that the working distance given may be longer than the
recommended (10 mm). It has been found that different EDX
manufacturers may have optimum collection below 10 mm. Each
system should be tested to find the optimum working distance before
using the heating stage.
FIGURE 9-40 POSITION OF THE HIGH TEMPERATURE GSED
EDX Performance
Elemental analysis can be performed while heating; the heat radiated
from the heating stage to the EDX detector is very small (under the
400 °C) and generally does not affect the EDX detector.
The sides of the crucible and the top edges of the stage interferes with
the collection of x-rays from the sample. Therefore, all EDX analysis
should be performed on the sample opposite to the EDX detector:
FIGURE 9-41 POSITIONING FOR EDX PERFORMANCE
Tilting the stage by no more than 5° toward the EDX detector will
improve x-ray signal collection as well. Count rates for EDX analysis
may be slightly lower than normal using this heating stage.
Window Contamination
Upon heating, certain samples may evolve gases or burn off various
residual components such as binders or fillers. If the EDX detector is
located close to the sample, these evaporated components may
condense onto the EDX window. To prevent this, keep the EDX
detector retracted away from the stage until it is needed.