Abstract
In the age of autonomous cars and electric planes, the reliability of intelligent systems is a priority for all stakeholders. Moreover, the downscaling of electronic components has generated renewed interest in the terrestrial atmospheric radiative environment. The atmospheric radiative environment is composed of numerous particles (neutrons, protons, muons, etc.). It is generated by Extensive Air Shower (EAS), a physical phenomenon during which a primary particle will generate many secondary particles. In order to better understand this environment, we decided, in this thesis, to model it and make measurements of its flux.Using the Geant4 Monte Carlo simulation toolkit and the Django framework, we built a model, RAMSEES (Radiation Atmospheric Model for Single Event Effect Simulation). RAMSEES provides fluxes of neutrons, protons, electrons, photons, and muons± at various altitudes in the atmosphere. We then improved RAMSEES by considering the impact of the ground and the angle of the primary particles on the secondary particle flows.In order to compare the RAMSEES results, we designed an instrument for stratospheric balloons BRAD (Balloon Radiation Analysis Device) and an experiment PIX (MiniPIX based experiment). We used PIX data collected during on four stratospheric balloon flights to compare the three atmospheric radiative environment models, MAIRE, EXPACS, and RAMSEES, from 0 to 40 km altitude.