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International audienceWe 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

A detector based on a silicon diode was developed to investigate the natural radiative environment. As the detector is embeddable, it has low power consumption and is lightweight and small. The instrument was tested under different neutron beams and used during stratospheric balloon flights. A comparison of the experimental results with Monte Carlo simulation results shows that the embeddable detector is a promising means of investigating the natural radiative environment.

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International audienceWe investigated the direction distribution of protons around 20 km of altitude by mean of stratospheric balloons. Our detection instrument was based on two large silicon diodes, which were differently tilted. Our measurements show that the proton flux is not isotropic and that protons have a higher probability to have a direction near the vertical axis than near the horizontal axis which proved the proton flux anisotropy. By simulation we then determined an empirical expression for the angular differential fluence of protons