−
14
−
ME12044A
Clicking on “OK” after setting the various values will initiate the scan, and a peak profile will be
displayed. After the scan is complete or is terminated by emergency stop button , a dialog box will
appear prompting the selection of a range. Specify, using the mouse, a range containing the peak
profile in which the monochromator axis is to be set, and click on “OK.” If no range is selected,
the system will find a peak from the range currently displayed, fit it using quadratic function, and
move the axis to the peak value. Pressing “Cancel” will cause the system to hold further action.
Enlarge the profile, read the values, and set each axis manually.
Normally, the Z-axis is set in the position at which a peak is detected in the Z-axis scan after the
goniometer is moved to the energy of the characteristic X-rays. If there are no appropriate
characteristic X-rays within the movable range of the goniometer, set the Z-axis using the
absorption edge. The procedure for doing so is as follows: load the standard sample, such as metal
foil, into the sample holder, and set the goniometer to the energy of the absorption edge. Monitor
the output of the I-detector, and define as the Z-axis position as that at which the X-ray intensity
falls in the case of a transmission layout, or as that at which fluorescence X-rays start being
emitted in the case of fluorescence layout.
The adjustment procedure for the
ω
-axis will be described below.
(1)
XG setup
The XG is set to 18 kV-10 mA. As the goniometer is positioned at 9200 eV, the XG should be set
to an X-ray-tube voltage of double that value. The tube current may be at its minimum.
(2)
Rough adjustment
Select Adjust
→
Monochromator. Open the Omega tag, enter Start = -3.0, end = 3.0, Step = 0.01,
FT = 0.5, and click on [OK]. The Omega-axis scan will begin. A peak should appear in the
proximity of 0
°
. However, if the peak position deviates significantly (
±
1
°
), reinstall the
monochromator.
When a peak is observed, perform fine scanning of the area of the peak.
Figure 6.7 Omega-axis Adjustment Tab
