783620H / 1013 5. MENU COMMANDS
Editing Nuclide Peaks
When a nuclide is selected in the working
.LIB
file, the right half of the Editing dialog shows the peak list. Note the column headers, Rank, Energy, and Percent. To sort the peak list by a particular parameter in the list, click the appropriate header. Be sure to check the flag settings in old libraries and edit if necessary.
To edit a peak, either double-click the peak in the right-hand list, or highlight it and click the Edit button. This will open the Edit Library Peak dialog
(Fig. 207). The Energy (keV), Gammas per 100
Disintegrations, Photon Flags, and Peak Flags will already be listed.
The Photon Flags are used to show the peak origin. Gamma Ray (G) and X-Ray (X) mean the peak energy is due to a nuclear or atomic transition, respectively. Positron Decay (P) is used for the 511 keV peak. Single-Escape (S) peaks are peaks for which a single 511 keV photon has escaped the detector. This can only occur for fullenergy peaks above 1.022 MeV. A Double-Escape
Fig. 207. Edit or Manually Add Library
Peak Values.
(D) peak is one for which two 511 keV photons have escaped the detector. Both single- and doubleescape peaks are broader than gamma-ray peaks. Neither can be used for activity calculations because the activity of the peak is not related directly to the activity of the full-energy peak.
Nonetheless, these can be included in the library to account for the peak in the spectrum.
The Not In Average (A) flag in the Peak Flags section of the dialog should be set for these peaks. All the peaks marked as Key Line (K) must be present before the nuclide will be listed as present on the report. If no lines are marked as key lines, the nuclide will be listed as present if the first line is in the spectrum.
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Adding Nuclide Peaks
To add a peak: Click the peak just below the desired insertion point in the peak list, then click
Insert.... This will open the Edit Library Peak dialog; all the fields will be blank. Enter the necessary information for the peak and click OK.
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To duplicate the operation of older versions of GammaVision, mark either no lines or only the first line as a key line.
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