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Manual V2.docx | Status 10.12.2015 | Version 1
4.2
Discriminator threshold
The discriminator threshold sets the level at which pulses from a CEM are counted or
ignored.
It is desirable to have this level as low as possible, so that all pulses are detected. Under
some circumstances, it is necessary to adjust the threshold to reduce the counted signal.
This may be performed to reduce noise from a channel, or to compensate for aging
differences between channels.
Note that the total intensity channel (1) of the Ferrum detector is read by the PHOIBOS 1D
analyzer, and that the spin channel (2) is read by the PHOIBOS Spin analyzer.
To set the discriminator threshold:
1.
Select the Device Controls view in SpecsLab Prodigy.
2.
Locate the PHOIBOS Spin or the PHOIBOS 1D.
3.
Click
Connect
if necessary to establish a connection with the detector.
4.
Expand the view.
5.
Select the
Std. Channel
tab.
Figure 10. Setting the discriminator threshold
.
6.
Enter a new value for the threshold. Normal threshold voltages are in the range 2–
10 mV. The maximum is 120 mV.
7.
Set the dead time. A normal value is 25 ns.
Summary of Contents for 2D-CCD
Page 1: ...User Manual Status 10 12 2015 Version 1 0 User Manual V1 0 October 19 2015...
Page 42: ...41 Manual V2 docx Status 10 12 2015 Version 1 Figure 22 The component spectra...
Page 53: ...52 Manual V2 docx Status 10 12 2015 Version 1 Figure 26 Quantum well state of 12 ML Pb Cu 111...
Page 57: ...56 Manual V2 docx Status 10 12 2015 Version 1 Figure 29 Wiring diagram for hardware type 156...
Page 85: ...84 Manual V2 docx Status 10 12 2015 Version 1 0...
