Once you define all the calculation input parameters, you will be able to run efficiency calculations. To define these parameters, you need to:

- Select an appropriate detector, container and geometry from the lists
- Define the radioactive source height and material (also its width, if it is different than the container inner radius)
- Choose the set of energies of interest for calculation
- Select the reference efficiency curve, if you want to calculate efficiencies (otherwise, only effective solid angles will be calculated)
- Choose the calculation precision.

With all these parameters set, you are ready to run calculations, or to save these calculation parameters and run them some other time, or even on some other computer.

To perform calculations from the currently selected parameters, simply click the button “**From current parameters**” on the “**Calculations**” ribbon tab.

Before calculation starts, Angle checks all input values for possible incompatibilities. If there are one or more incompatibilities in the input parameters, such as the container not compatible with the detector (for example, if you try to use a well detector with a Marinelli container), you will get the error message and the calculations will not be performed.

If all input parameters are correct, Angle will ask for the name of the file where the output results will be saved and the calculations begins. While calculating, Angle displays information about the calculation, as shown in the next figure.

The first label shows the source of the input parameters – the name of the parameter file or “Selected calculation parameters” in cases when running calculations from current parameters (more about the parameter files is in “**Saving input parameters**”). The second label shows the name of the output file.

Calculations take place in three phases:

**sample geometry**calculations,**cascade summing**corrections calculations and**reference geometry**calculations (only in case a reference efficiency curve is selected).

Usually, calculation times are very short. Sometimes, depending on the calculation precision set and the counting arrangement used in calculations, calculations can take longer than a few seconds. In those cases, Angle will display the histogram with currently achieved precisions for each of the selected energies. The bars for energies for which the specified precision level was reached are displayed in green, as shown in the following figure.

Calculations can be canceled anytime by clicking the “**Cancel**” button

If you check the option “**Turn off the computer when done**”, the computer will be shut down automatically when calculations finish. This is useful for time consuming calculations (e.g. long batch jobs), where computers are left unattended to finish calculations. Once all calculations are finished, the shut down dialog will be displayed:

The shut down dialog will start a 30-second countdown, after which the shut down procedure will be initiated. During this period, it is possible to cancel the shut down, or even force it before the timer reaches zero.

On Windows Vista and newer operating systems, Angle can display the calculation progress on the Windows Taskbar. This is useful in case of lengthy calculations (e.g. running many calculations at once), so you can monitor the progress of calculations while working in other applications, even if the Angle window is not visible. To see how to enable or disable this functionality, see Configuration section.

After the calculations are finished, a window with the calculation results will be displayed automatically.

The calculation results window displays all input parameters used for calculation: detector, container, reference efficiency curve, etc. To see the details for each of them, simply click on the name of the parameter, or the “info” button on the right-hand side of it.

The input parameters containing detailed information can be recognized by the “info” button at the right-hand side. Also, the cursor changes its shape to a pointing hand when moving over these parameters.

The scaled preview of the whole counting arrangement is displayed in the right-hand part of the calculation result window. As with other previews, you can also zoom-in and zoom-out the preview image, pan it and export it to various raster and vector graphics formats (read more in the Data entry section).

Calculation results are shown in a table under the “**Calculated efficiencies**” tab: values of the effective solid angle (Ω_{eff}) and efficiency (ε_{p}) are shown for each energy from within the given energy set, as well as the estimated calculation precisions.

The ε_{p} values will be calculated only if the reference efficiency curve is defined. Otherwise, only Ω_{eff} values are calculated.

Calculated efficiencies can be copied to the Clipboard by clicking the “**Copy to Clipboard**” button and then pasted to other programs, for example to spreadsheet or word processing software.

Cascade summing corrections (CSC) for all nuclides are displayed under the “**Cascade summing corrections**” tab, as shown in the following figure:

In order to easily locate nuclides of interest, the results can be sorted using the “**Sort nuclides by**” drop-down. Nuclides can be sorted by:

**symbol**,**atomic mass**, and**energy**.

Depending on which of these three options is selected, the list on the left-hand side of this tab will contain nuclides sorted by name or by atomic mass, or list of energies. Upon clicking the values in this list, the table right to it will display the appropriate values:

**nuclide**or**energy**,**correction coefficient**,**branching ratio**(emission probability), and**corrected branching ratio**.

Calculated cascade summing corrections can be copied to the Clipboard and pasted to other programs by clicking one of the following two buttons:

- “
**Copy coefficient to Clipboard**” button will copy the values for the selected nuclide/energy. - “
**Copy all values to Clipboard**” button will copy the values for all nuclides.

Since the list of nuclides supported by Angle is rather extensive, it is possible to select just a subset of these nuclides that interest you. To do that, use one of the options from the pop-up menu, which you can open by clicking the “**Nuclides of interest**” label.

The first option from the pop-up menu (“**All nuclides**”) will show the data for all nuclides. To select the previously saved set of nuclides, you can simply choose one using the “**Saved sets of nuclides**”, or locate a file with the nuclide set using the “**Load saved set of nuclides...**” option. The second option from the pop-up menu (“**Edit set of nuclides...**”) lets you specify a new set of nuclides of interest.

You can add the nuclides to the new set one by one by selecting it on the left-hand list and clicking the “**Add >**” button, or simply by double-clicking it. You can filter the list of nuclides using the “**Filter nuclides**” field. For example, if you type “Na” in this field, you will get two nuclides: *Na-22* and *Na-24*, which you can both add to your set by clicking the “**Add all >>**” button. To remove the selected nuclides, you can use the “**< Remove**” and “**<< Remove all**” buttons.

When you finish defining the nuclides of interest, you just need to give your set a name and click the “**OK**” button. You will be prompted if you would like to save the set of nuclides to a file for future use.

The files with the calculation results (“.outx” extension) contain the full list of nuclides, regardless of the selection of the selected set of nuclides. Therefore, you can switch between the different nuclide groups and see the cascade summing corrections without having to re-run the calculations.

Calculation results can be opened and reviewed anytime later by re-opening the calculation result files. To do this, choose the “**View calculation results**” option from the “**Calculation**” ribbon tab and select the calculation results files to display.

It is possible to select more than one calculation results file:

To select multiple files, use any of the following standard Windows procedures (or their combination):

- By clicking a file name while holding the keyboard
**Ctrl**key you can select/deselect one or more files. - By clicking one file name and then clicking on another file name while holding down the
**Shift**key, all files between those two will be selected.

By pressing the **Ctrl+A** key combination you can select all files in the folder.

If you select more than one file to display, the calculation results window will contain a list of files in the left-hand part of the window. By clicking a name of a file, the results from that file will be displayed in the right-hand part of the window. This option is useful when comparing the results of calculations or when transferring the results to another application.

When opening the calculation results from previous versions of Angle, the window with the calculation results will not contain the precision estimation, or cascade summing corrections, since they are introduced with Angle 5.

To copy the results from all files at once, click the button “**Copy all results to Clipboard**”, located under the list of files.

To print calculation results simply click the “**Print calculation results**” button. The resulting one-page document will contain the results, together with the summary of the input parameter data, counting arrangement schematics, and calculated efficiency curve (if efficiencies were calculated).

If you want to print a detailed report, you can do it by clicking on the “**Print calculation report**” button. The report will contain the results, as well as all the input parameter data used in calculations – thus making the results traceable to the input values.

Traceability of results down to input parameters is important for e.g. validation and/or accreditation purposes.

Angle 5 introduces another new feature – now you can see and export the graph of the calculated efficiency curve. To see it, click on the “View efficiency curve” button, located just below the preview image in the calculation results window. The efficiency curve graph window is shown in the next figure.

The graph shows both the calculated efficiencies for selected energies (red square markers) and the fitted efficiency curve (solid blue line). The *reference efficiency curve* is shown as well (dashed blue line). Angle uses the same intervals and polynomial orders for both curves.

To be able to calculate efficiencies, Angle needs you to specify the reference efficiency curve.

As with other previews, you can also zoom-in and zoom-out the preview image, pan it and export it to various raster and vector graphics formats (read more in Data entry section).

The calculation results are saved in XML format by default (with the “.outx” extension). The calculations can also be saved to widely used JSON and YAML formats by clicking the “**Save in JSON format**” and “**Save in YAML format**” buttons, respectively.

The calculation results can be exported to **ORTEC GammaVission** format, simply by clicking on “**Export to ORTEC GammaVision**” button.

Export to ORTEC GammaVision will be possible only when efficiencies have been calculated, i.e. when a reference efficiency curve is defined. Otherwise, the “**Export to ORTEC GammaVision**” button will be disabled.

Calculation results can also be exported to the Canberra **CAM file** format, simply by clicking on “**Export to Canberra CAM file**” button.

Export to Canberra CAM file will be possible only when efficiencies have been calculated, i.e. when a reference efficiency curve is defined. Otherwise, the “**Export to Canberra CAM file**” button will be disabled.

Canberra software must be installed on your computer in order to be able to export CAM files from Angle.

All calculation parameters can be saved to a file and be used for further calculations later. This is convenient, for instance:

- When calculations will not be performed immediately.
- For preparing calculations which will be performed on another computer.
- For preparing the inputs for multiple calculations at the same time (batch jobs).

To save calculation parameters to a file, select all calculation parameters in the same way as when running calculations and click the button “**Save calculation parameters**” from the ribbon tab “**File**”, or by pressing the **Ctrl+S** key combination on the keyboard.

Before saving, Angle checks all input values for possible incompatibilities. If there is an incompatibility in the input parameters, such as an invalid detector-container combination (for example when using a well detector with a Marinelli container), the error message will be shown and file will not be saved.

To perform calculations from one or more saved parameter files, click on “**From saved calculation parameters**” from the “**Calculations**” ribbon tab.

After choosing one or more previously saved calculation parameters files, the calculation begins. The output files will have the same name as the input files (except for the extension, which will be “.outx”).

If you selected more than one file for calculations, the dialog box displaying calculation progress will additionally contain the information about the overall progress, the number of files being processed and the elapsed time for the overall process.

Output files will have the same names as the input ones. If output files with the same names exist, they will be overwritten without warning.

After the calculations are finished, the output results will be automatically displayed for all selected files, except in cases when an automatic computer shut down is requested.

Since the calculation results files contain all input parameters, it is possible to run the calculations using them as input files. This can be convenient to re-run the calculations performed in older versions of Angle in order to get the coincidence summing corrections or precision estimations, or to convert the parameters to XML format from the legacy binary files (Angle 3 and earlier).

To perform calculations from one or more calculation result files, click on “**From saved calculation parameters**” from the “**Calculations**” ribbon tab and select “**Calculation results**” file type.

When running calculations from files generated with previous versions of the Angle, the default precision of 1% will be used.