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This library,
GVDEMO.LIB
, is now loaded into the computer memory as the working library, and is the library that GammaVision will use for all analyses until you change it (by recalling another library from the Library menu or from within a sample defaults file as discussed later). It is automatically reloaded each time GammaVision is started.
3.2.4. Setting the Analysis Parameters
Click Analyze, then Settings to open the submenu shown in Fig. 17. Select Sample Type....
This will open the Sample Type Settings dialog shown in Fig. 18, which allows you to specify the parameters that control analysis of the currently displayed spectrum. In routine use, these would not be changed except for the sample description. Entry of sample weight and sample description can be automated using the Acquisition Settings... command under the Acquire menu.
Fig. 17. Choose Sample
Type... Command.
Fig. 18. Sample Type Settings Dialog, Sample Tab.
We will use the Nuclide Library just loaded in computer memory by leaving the Internal checkbox marked. Similarly, to use the Calibration that was saved with the spectrum in
GVDEMO.SPC
, leave this Internal checkbox marked also.
Select the Report tab to view the reporting, uncertainty reporting, and output options (Fig. 19).
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Fig. 19. Report Tab.
Mark all of the Reporting Options except ISO NORM, and make sure the Total option is selected in the Uncertainty Reporting section.
To send the output to a printer, go to the Output section of the screen and click the Printer radio button to mark it with a dot.
To send the output to a file instead, click the File radio button, and leave the asterisk ( * ) as the filename. Leaving the asterisk ensures that the report file will have the same filename as the spectrum (however, it will have the extension
.RPT
). You can, however, enter a path and filename in this field to force the report to be saved to the filename you specify.
To send the output to a text processing program, such as Windows Notepad (which is the default), click the Program radio button.
Click all four checkboxes in the Reporting Options section of the screen, then click OK.
Select Analyze and Entire spectrum in memory.... Spectra can be analyzed in the buffer (as we have done here), directly from disk, or in the Detector memory (when the Detector is not count-
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783620H / 1013 3. GETTING STARTED — A GAMMAVISION TUTORIAL
ing). For spectra in the Detector memory or a buffer, the displayed spectrum is the one being analyzed.
When the analysis is complete, the results will be printed or saved to disk, according to your selection on the Report tab on the Sample Type Settings dialog (the report is covered in
Chapter 7). They can also be graphically displayed by selecting Analyze and Display Analysis
Results..., then clicking on Open to load the analysis results file,
GVDEMO.UFO
. This will overlay the peak shapes on the spectrum data, open the Analysis Results Table for the spectrum, and display the Analysis Sidebar superimposed over the Status Sidebar, as shown in Fig. 20.
Zoom in to see more details.
Click on the peak at 136 keV and expand the display horizontally with Zoom In. Put the mouse on the
241
Am (59.6 keV) entry in the peak list table and click. The marker will move to that peak in the display. You can use the scroll bars on the peak list window to show other energies, and then when you click the energy, the display will show that peak.
In this mode, you can also use the buttons on the Analysis Sidebar to move the marker in the spectrum. For example, click
241
Am in the peak table, then click (the right-hand
Energy button in the Library Peak section of the Analysis Sidebar) to put the marker on the next-highest-energy library peak, which is the 70.8 keV line of
203
Hg.
Now click to go to the next-highest-energy peak in the library for
203
Hg, then click again to get to the 279 keV peak. The within Nuclide buttons are useful for checking if other peaks for the nuclide exist so that you can confirm their identity. The button moves the marker in reverse order through the peaks for the selected nuclide.
The buttons are used to select the spectrum peaks that are not associated with a library energy. This is useful to see if there are any unidentified spectrum peaks that should be considered in the complete analysis.
The buttons are used to select the regions with overlapping peaks. With these, you can easily check how the analysis of complicated regions was handled.
Now, select Library and Select Peak... to show a list of the peaks in the current library.
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You can use this list of peaks to move around in the spectrum. Click the Library List window’s down arrow to scroll down to 88 keV
109
Cd. Now click this entry and the display will update to this peak.
9
This can be a different library than the one used in the analysis of the spectrum.
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