Linear and nonlinear data tab
This tab contains all the data necessary for quick overview of the calibration's most important numeric data. These comprise the current status (modified or unmodified), the calibration point list as well as the optional additive nonlinearity applied.
The point list contains two or more editable calibration points, to which a linear fit is performed, thus determining a channel – keV calibration line. If only two points are used, the line will necessarily go through the points. If more than two points are specified, a least–square fit is performed, in order to determine the optimum calibration line between scattering points.
The nonlinearity curve provides a fine tuning, to compensate system nonlinearity. See further details in section “System nonlinearity analysis
To delete a specific calibration point, select it by clicking on it with the mouse, or make it active by pressing the up or down cursor arrow keys, and click Delete button.
Entering new points manually
If you do not want to use HyperLab's visual calibration point adding facility, just want to enter predefined calibration points, press the (cursor down) key repeatedly, while you leave the last point's row, and a new, empty row automatically created. Type in the proper values, then press (cursor up) key to leave the edited calibration point row. If you want to enter a completely new calibration, first remove all calibration points, and add them one by one.
Modifying channel positions
To modify the channel position of a specific point, manual editing or borrowing may be used.
To edit the value by hand, just click on the channel number value, and type the new number. To borrow the exact peak position value from a fitted spectrum peak, click the ellipsis [...] button beside the channel value.
The spectrum fitting window appears now. Click with the position retrieval tool on a peak. The energy calibration editor appears again, and the clicked peak's fitted position will be used as the channel value of the calibration point. To cancel the borrowing process, press Esc.
Modifying energy values
Similarly to channels, energy values may also be modified by either manual editing, or by getting the exact values from HyperLab's nuclear data database. Manual editing may be initiated by simply clicking on an energy value and typing its new energy position in keV.
If you want to use a value from the nuclear database, click on the energy value, then on the ellipsis [...] button beside the energy value.
The calibration line selector window appears now. It contains decays and radiations from the database.
When this window firs appears, you can type in the first letters of the element, when the decay lister will select the appropriate element. After the element is selected, open it by clicking on the [+] at the left to show up its decays. Now click on one decay and its radiations will be listed on the right.
To select a radiation, click its line in the Available radiations table, then click OK. Alternatively, you can simply double-click on the radiation's data row.
The radiation list can be sorted by the Intensity and the Energy radio buttons at the top of the list as required. When you selected an energy row, the energy calibration editor window appears again, displaying the modified energy value.
Adding new points by visual selection
HyperLab also makes it possible to add a new calibration point via a more convenient method. If you click New button under the table of calibration points, HyperLab first displays the spectrum evaluation window, where you can select a fitted peak for position, then instantly shows the calibration line selector window, in order to select a calibration line from the nuclear database. This way addition of a new calibration point may be accomplished rather quickly.
The problem of missing gamma lines
It may be disturbing that some of your well-known calibration peaks are not provided in the calibration line selector window. This may be due to its missing radiation usage flag.
HyperLab uses a gamma line for energy calibration purposes only if that radiation is equipped with “Use for energy calibration” flag. See further details in section Nuclear data library management