Acquiring Spectra With The Psi Diagnostic Program - Pyramid D100 User Manual

PSI System Controls and Diagnostics
Figure 8. D100 window device tab showing communication status, version numbers and code
upload utility.

9.4 Acquiring spectra with the PSI Diagnostic program

If you have the parts available to hand, you can connect up a scintillator and photomultiplier on
the bench as shown in figure 3. It is best if you can use parts that are known to work, rather than
untested ones. Check that the high voltage can be enabled and is stable. Finally, with a suitable
test radiation source, you can acquire an energy spectrum, and calibrate the energy scale.
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Figure 9 shows an example Na gamma spectrum. It is the result of binning the pulse areas into
1024 equal regions. Clicking and dragging in the spectrum window defines a region of interest
(not to be confused with the real-time histogramming regions of interest described later). The
software assumes you have highlighted a defined peak, and attempts to fit a Gaussian curve plus
a sloping background to the data. The position and full-width half maximum of the fitted peak
are displayed. Right-clicking brings up a menu, and you can select the calibrate option to use
this peak in an energy calibration, presuming you know its true energy. If you repeat this
process with a second peak, a linear calibration will be performed immediately.
D100 User Manual D100_UM_081027 Page 23 of 46