FEIGN: a package to estimate the geometric efficiency of gamma spectroscopy setups in spent nuclear fuel measurements

feign is a python package for estimating the geometric efficiency in passive gamma spectroscopy measurements of spent nuclear fuel assemblies. It implements a 2D point-kernel method without build-up factors (ie. an "uncollided F5 tally" as known by MCNP users). The name feign implies that the program pretends to be a transport code, however it is rather a ray-tracing code.

It is intended for nuclear safeguards specialists and nuclear engineers who want to get a quick estimate on the geometric efficiency in their passive gamma setup. It might be also useful to people working with passive gamma emission tomography of spent fuel.

The feign API allows the user to define the geometry of a rectangular fuel assembly, which is built of pins (nested annular material regions). The user also defines the composition of materials present in the simulation, the detector points where the efficiency needs to be evaluated, and optionally collimators and absorber elements.

As a package, feign provides

• basic 2D geometry classes (Point, Segment, Circle, Rectangle)
• classes to describe materials, fuel pins, rectangular fuel assemblies, detectors and absorbers
• methods to perform the ray-tracing and estimating the geometric efficiency.

Installation

feign can be installed by downloading the zipball from github.

bash pip install https://github.com/ezsolti/feign/zipball/master

Installation was successfully tested on Linux and Windows.

Uninstall it with the command

bash pip uninstall feign

Dependencies

• NumPy
• Matplotlib

Data

Besides the installation you will need mass attenuation coefficients. You can download some files for testing from the data folder. Further information on how to obtain your own data is an the documentation site. When you have gathered your own datafiles, you can link them to Material() objects with the following method:

python uo2=Material('1') uo2.set_path(('/yourpath/UO2.dat',1))

set_path expects a tuple, the first element is the path to the data file, and the second element clarifies which column should be used from the file (since you might have several columns, for example attenuaton with or without coherent scattering).

Getting started

The basic functionality and the theoretical background is summarized at the documentation site

Examples

Several examples can be found in the examples folder or at the documentation site

Docs

API documentation, examples and theoretical background is covered at ezsolti.github.io/feign

Contributing, bugs, suggestions

Any reported bug or suggestion is appreciated, please open a new issue. If you would like to contribute, do not hesitate to do so, just include tests.

Tests

Several tests can be found in the tests folder, run them with

bash python3 -m unittest discover tests/

Licence

This work is licensed under the MIT License (see LICENSE)