Advanced software for gamma spectrometry

Angle 4 is advanced quantitative gamma spectrometry software. It has been in use for 28 years in numerous gamma spectrometry based analytical laboratories worldwide.

Angle allows for the accurate determination of the activities of gamma spectroscopic samples, and thus is used for the quantification (i.e. spectrometry) of measurements. This is achieved by the calculation of detection efficiencies based on a solid and well known theoretical background, using the so called "efficiency transfer" (ET) method. In doing so, Angle calculates efficiencies for any given sample based on any other (reference) source. ET is a semi empirical approach – it is a combination of both experimental evidence and mathematical elaboration.

Broadly applicable

Angle is broadly applicable (in environmental monitoring, nuclear industry, waste management, regulatory control, nuclear security and safeguards, medicine, research, education etc.) and extremely flexible – it fits to user’s needs and to most common laboratory circumstances/capabilities.

Angle is open and it does not represent a "black box" for the user: all parameters of the detector, sample, counting geometry etc. are under control and subject to modification.

All your detectors in one place

In your Angle copy you can specify any number of detectors you are using, including semiconductor (Ge) and scintillation (NaI) ones.

Angle supports six Ge detector types, and two NaI types. Both cylindrical and well detectors are supported. This covers vast majority of gamma-spectrometry systems in operation nowadays, which are built around these detector types.

There is no need for detector factory characterization and re-characterization; detector calibration is done by the user in a single and straightforward process, based on experimental evidence involving reliable calibrated sources. The choice of calibrated sources is flexible and up to the user – in principle, any source(s) can be used to that aim.

Enhanced user interface

Angle has an intuitive graphical user interface, which makes it easy to use and to learn. It is designed and organized to be logical and intuitive.

Taking into account the extensive users’ feedback, many "touches" have been added to ease its use and to avoid misunderstandings and blunders in data entry.

Demo calculations

Angle 4 comes with a set of eight predefined demo detectors, one for each supported type. Demo detectors can be used for calculations even in demo mode, that is, even if Angle is not registered.

Demo calculations enable the users to run calculations and evaluate the results, so as to become more familiar with the scope and capabilities of the software without/before being registered.

This feature makes Angle a great educational tool which can be used for experimenting with virtual detectors in a virtual laboratory.

Easy integration with third-party applications

Angle 4 introduces a completely new format for all its file types, based on the XML syntax. The new format allows easy integration with third-party applications (e.g. in-house developed software), or import to spreadsheet or even word processing software.

Being simple text files, they are also human-readable, so you can also use a simple text editor to view or edit them.

Together with the new XML-based file format, a set of command line parameters allows easy integration. This enables, for instance, thousands of calculations to be done in a couple of hours batch, making it suitable for research and scientific purposes (e.g. error propagation studies, control and optimization of spectrometry parameters, tracking sources of systematic errors, etc.).

Discrete reference efficiency curves

In Angle 4 you can define a "discrete efficiency curve", meaning that you actually do not need to interpolate the curve, but to use the efficiencies for the exact energies which exist in the experimental points.

In cases when efficiency calculations are needed only for energies defined by their reference experimental points, their exact efficiency values will be used (instead of interpolated ones), leading to better accuracy for the given energies; this applies particularly well for NaI detectors.


Using Angle 4, you are able to see the scaled image of your detectors, containers, geometries and even complete counting arrangements. The image is proportional, which is useful for noticing blunders in parameter entries, which would otherwise be hard to detect.

You can easily zoom in and out of the preview image and pan around it, as well as export it to one of four graphics formats: two raster (JPEG and BMP) and two vector (WMF and EMF), for use in your documents or web pages.

In Angle 4 now you can also see and export the graph of the calculated efficiency curve. It shows both the calculated efficiencies for selected energies and the fitted efficiency curve, together with the reference efficiency curve.

Data import and export

Angle 4 allows you to share your data easily among different computers using the new import and export features. This saves time taken up by re-typing the parameters and avoids any possible mistakes caused by this.

It is now also possible to import parameters for detectors, containers, geometries, reference efficiency curves and energies from calculation parameter files and calculation results files.

Additionally, now it is possible to export the results to ORTEC GammaVision – both to efficiency calibration (EFT) and geometry correction (GEO) files.

Angle 4 also supports reference data import and export from and to both ORTEC’s and Canberra’s spectrum emulation software.

Calculation reports

Calculation results can be easily printed. It is possible to print the calculation results with the summary of all input parameters, counting arrangements schematics, as well as calculated efficiency curve.

A detailed report can be printed as well. The report contains both the results and all the input parameter data used in calculations. This makes the results traceable to the input values.

Multilanguage support

Angle 4 is a multilanguage application. You can easily switch among different languages anytime, from the configuration dialog box, with just a few clicks.

Currently, you can switch between English, French, Spanish, Russian, Chinese and Japanese language.

Prompt and elaborate user support

During more than 20 years on the market, Angle users have been receiving prompt direct support for any Angle-related issue – from simple queries to complex matters.

The Angle team is devoted to helping and assisting anytime – via email, but also phone calls, video conferences, etc, as needed.