Installation¶

Getting data¶

Mass attenuation coefficients can be obtained from the XCOM webpage, or by downloading the XCOM software. When creating your own datafiles, do not forget to include an energy grid which covers your energy region of interest, because feign is unable to extrapolate the mass attenuation coefficients. Also try to use a reasonably dense energy grid which can catch the energy dependence of the mass attenuation coefficient, otherwise the interpolation will not be a decent approximation.

When creating your own data files, make sure that the columns are separated by white spaces (eventhough XCOM allows for separating with “|”).

Test data files are also available at feign’s github repo. Mass attenuation coefficients are there for some materials common in passive gamma spectroscopy of nuclear fuel (uranium-dioxid, water, air, lead, aluminium, copper, stainless steel). Save these files to your prefarred location and include the paths when creating Material() objects. When you have gathered your own datafiles, you can link them to Material() objects with the following method:

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).

Some explanation on how to create mass attenuation data with XCOM from Serpent2 bumat files is also under development and will be added soon.