Abstract
We developed an integrated silicon detector to be embedded in a stratospheric balloon in order to investigate the radiative atmospheric environment. The detector was calibrated with a Californium source, and it was fully characterized under neutron beams which produced various secondary ionizing particles. Differential detection cross sections for different neutron beam energies were shown to be in good agreement with simulations performed with the MC-Oracle code. We performed four stratospheric balloon flights (with ESA and CNES) and confirmed the correlation between the count rate and the altitude. Moreover, we observed that the radiative environment is not isotropic and demonstrated the potential of our tool for investigating the radiative atmospheric environment. These results are useful for estimating the particle flux that affects electronic devices and onboard aircraft systems.