Setting and Adjustment
64
MiniFlex 600: Benchtop X-ray Diffractometer
HV/PHA Adjustment of Scintillation Counter (SC)
X-rays entering the scintillation counter contain unnecessary X-rays, such as, not
only the characteristic X-rays but also the continuous X-rays and X-ray
fluorescences from the sample. Pulse height analyzer (PHA) is used to cut
unnecessary X-rays electrically by using the difference in height of the pulse
generated in detector caused by the energy of X-rays.
When using the X-ray tube for a long period of time, the fluorescent material of
the SC deteriorates. This causes the height of the pulse of the characteristic
X-ray to change and cause the pulse to not pass the PHA. This is the same with
when the X-ray tube (target) is changed. Readjustment of HV and PHA of the
SC is necessary to let the characteristic X-ray pass the PHA efficiently.
When the type of X-ray tube (target) is changed, change the K
β
filter as well.
(K beta filter/Target= Ni/Cu, Fe/Co, Mn/Fe, V/Cr)
1
Set the setting jig (with Si) on the sample holder.
2
Select Tasks – Package Measurement.
①
Select
Maintenance
–
SC Detector Adjustment,
and then select
HV/PHA Adjustment (BB)
at the lower area.
②
Enter the peak position of Si (111) (see Fig. 6.3.1) and click the
Execute
button to execute the HV/PHA adjustment.
③
A message confirming whether to register or not will appear after the
adjustment is completed. Press the
Yes
button to register.
④
After the registration is completed, press the
OK
button to close the
window.
Fig. 6.3.1 HV/PHA adjustment (SC)