This page shows the step-by-step process of the Calibration Wizard for a typical calibration (Energy, Resolution, and Efficiency) as well as the Multiple Source and Single Source TCC Calibrations.

The calibration wizard can help operators of GammaVision perform a complete calibration process. It is a step-by-step set of dialog boxes which will ultimately result in a calibration, be it just a new energy calibration or a complete True Coincidence Correction calibration. If performing the calibration for the first time or doing a new calibration, the wizard even takes control of the hardware, sets the count time, and waits until the counts are completed. It then performs the necessary analysis and gives the operator a visual feedback of the success of the calibration.

The wizard also works on "stored" files. This means that the user of GammaVision can perform a calibration on a file stored on disk. Since acquiring some source data can take many hours, some operators will want to collect the data independent of actually performing the calibration steps. No problem! The wizard simply asks for the same information leaving out the steps where data acquistion is involved.

Energy, Resolution, and Efficiency – the Standard Calibration

Step 1 The first step in any of the calibration routines is to select the Calibration Wizard from the Calibrate menu in GammaVision:

Step 2 Next, select the radio buttons next to "Create New" for both the energy and efficiency calibration.

Step 3 Select the library which GammaVision will use to perform the automatic energy calibration by pressing the "Browse" button. This can be any valid library file. Enter a name for the source which will also be used as the prompt for the calibration step. Finally, enter the data acquisition time in seconds (Live Time).

Step 4 Select the Efficiency Table File (EFT) by pressing the "Browse" button or create a new file by pressing the "Edit" button which will bring up the Certificate File Editor. Also select the library as in Step 3. Enter a name for the source which will be used as the prompt. Enter the count time in seconds. If you are using the same source to do the Efficiency calibration that is used for the energy calibration, do not check the box that says "Clear Data before Start". This will save time in doing the actual data acquisition.

Put the source in place when prompted.

Step 5 Verify all the curves and fits for the data are valid. From this final dialog box, the calibration file can be saved and the wizard completed by clicking "Finish."

Energy, Resolution, Efficiency, and TCC– the Multiple Source Method

Step 1  The first step in any of the calibration routines is to select the Calibration Wizard from the Calibrate menu in GammaVision:

Step 2 Next, select the radio buttons next to "Create New" for the energy, efficiency, and TCC calibration. Note that anytime a "TCC Calibration" is selected that "Efficiency" is also automatically selected. An efficiency calibration has to be done with every TCC calibration.

Step 3 Select the library which GammaVision will use to perform the automatic energy calibration by pressing the "Browse" button. This can be any valid library file. Enter a name for the source which will also be used as the prompt for the calibration step. Finally, enter the data acquisition time in seconds (Live Time).

Step 4  Select the Efficiency Table File (EFT) by pressing the "Browse" button or create a new file by pressing the "Edit" button which will bring up the Certificate File Editor. Also select the library as in Step 3. Enter a name for the source which will be used as the prompt. Enter the count time in seconds. If you are using the same source to do the Efficiency calibration that is used for the energy calibration, do not check the box that says "Clear Data before Start". This will save time in doing the actual data acquisition.

For the TCC Calibration Method, select the "Multiple Point Source Method". This will prompt the operator to do the Peak-to-Total Calibration. (See Steps 5 and 6).

Step 5 Select the Peak-to-Total certificate file from the next dialog box. A new PTT file can be created or the existing one modified by selecting the "Edit" button. Doing so will bring up the dialog box in Step 6.

Step 6 Enter the information for the Peak-to-Total calibration. The information needed is:

• Isotope Name
• Energy of Peak
• Count time for the Isotope
• Count time for the background count

The operator also needs to select whether or not there is an absorber between the source and detector (in most cases, the operator should select "Point with Absorber").

Put the source in place when prompted.

GammaVision will first prompt for the Energy Calibration source, then the Efficiency Calibration source. After these are done, a background count will be made. GammaVision will prompt to remove all sources before continuing. After the background is done, each of the PTT sources will be counted individually. In this example, Am-241, Cs-137, Mn-54, and Zn-65 in that order.

Step 7  Verify all the curves and fits for the data are valid. From this final dialog box, the calibration file can be saved and the wizard completed by clicking "Finish."

Energy, Resolution, Efficiency, and TCC– the Single Source Method

Step 1  The first step in any of the calibration routines is to select the Calibration Wizard from the Calibrate menu in GammaVision:

Step 2  Next, select the radio buttons next to "Create New" for the energy, efficiency, and TCC calibration. Note that anytime a "TCC Calibration" is selected that "Efficiency" is also automatically selected. An efficiency calibration has to be done with every TCC calibration.

Step 3  Select the library which GammaVision will use to perform the automatic energy calibration by pressing the "Browse" button. This can be any valid library file. Enter a name for the source which will also be used as the prompt for the calibration step. Finally, enter the data acquisition time in seconds (Live Time). For this calibration, since all fits will be done at the same time with the same source, choose a long count time such as 10,000 seconds.

Enter a name for the source which will be used as the prompt. Enter the count time in seconds. Since we are using the same source to do the TCC calibration that is used for the energy calibration, do not check the box that says "Clear Data before Start". This will save time in doing the actual data acquisition.

Finally, select type of source being counted: Point or Extended, and whether or not an absorber is present. If in doubt about the absorber, choose "Present" for the best fit to the data.

Put the source in place when prompted.

Step 5  Verify all the curves and fits for the data are valid. From this final dialog box, the calibration file can be saved and the wizard completed by clicking "Finish."