EcoMug: An Efficient COsmic MUon Generator for cosmic-ray muon applications

Applications of cosmic-ray (CR) muons have grown in numbers in the last decade. Measurements of flux attenuation (radiography) and scattering angles (tomography) of CR muons have been successfully applied to the inspection or monitoring of large natural and civil structures, to the search for heavy metals in container and trucks, to the control of nuclear wastes, and much more. In the present work, a new Monte Carlo generator of CR muons, called EcoMug and specifically designed for muon radiography and tomography applications, is presented. It is a header-only C++11 library, based on a parametrization of experimental data. Unlike other tools, EcoMug gives the possibility of generating from different surfaces (plane, cylinder and half-sphere), while keeping the correct angular and momentum distribution of generated tracks. For example, this flexibility allows for a very efficient generation of nearly horizontal muons, of great interest in many muon radiography and tomography applications, by using cylindrical or half-spherical generation surfaces. Finally, EcoMug also allows the generation of CR muons according to user-defined parametrizations of their differential flux. Main features of EcoMug, its mathematical foundation, as well as applications to selected study cases are presented.