5 OPERATION
EM210F-1
5-43
5.5 ELECTRON
DIFFRACTION
5.5.1 Selected Area Diffraction
An electron beam passing through the small area limited by a field limiting aperture
forms a selected area diffraction pattern.
1.
Obtain a conventional image on the screen.
2.
Depress the SA MAG switch (R1-
②
) to obtain the SA MAG mode.
3.
Manipulate the MAG/CAM L knob (R1-
⑤
) to select a magnification to be
used.
4.
Bring a field of view to be used to the screen center using the triangle buttons
or trackball (
F
Sect. 4.2.5).
5.
Insert a field limiting aperture into the electron beam path.
A selected area image appears on the fluorescent screen.
6.
Turn the BRIGHTNESS knob clockwise to darken the image as much as
possible.
7.
Depress the SA DIFF switch (R1-
②
) to obtain the SA DIFF mode.
A diffraction diagram appears on the screen.
8.
Manipulate the MAG/CAM L knob (R1-
⑤
) to select a camera length to be
used.
9.
Manipulate the DIFF FOCUS knob to make the diagram clear.
a: Selected area image
b: Selected area diffraction image
Fig. 5.39 Selected area diffraction
