JEOL JSPM-5200 Instructions Manual page 337

■ High-speed Fourier Transformation Analysis (FFT)
FFT is performed on an image that has a periodic structure, such as a crystal, or a
rearranged structure, in order to obtain a diffraction pattern. It is also possible to apply a
mark to the acquired diffraction pattern, and perform reverse Fourier analysis of
specified components alone.
1.
Click on the FFT shortcut icon.
2.
Select Forward on FFT Window displayed.
Fourier transformation starts. Upon completion of Fourier transformation, a diffrac-
tion pattern appears on the display.
3.
If the spots of the diffraction pattern are dark, making them difficult to see,
select Contrast × 2 to increase the contrast.
If you wish to remove unwanted spots and perform a reverse Fourier transformation,
next carry out steps 3 to 6 below.
4.
Click on Add.
5.
Apply a mask window to a valid spot.
TMPM5200-2
Contrast × 2 generates double brightness when selected once. You can make this
selection any number of times.
To set a mask window, move the cursor to the center of the spot, and click the
left mouse button. Next, move the cursor a distance equal to the radius, then
click the left mouse button, and a window appears.
６ ANALYSIS OPERATION
r
Center
6-7