PIX: An Instrument to Measure Atmospheric Ionizing Particles Based on a Single MiniPIX Sensor

This article presents the PIX instrument based on a Raspberry Pi and a MiniPIX device dedicated to making measurements of ionizing particles onboard stratospheric balloons. The hardware and software parts of the PIX instrument are described. All the characteristics of the instrument are given in this article. The three flight opportunities are also presented, with the associated measurements. The methodology to calculate fluxes based on measurements is explained. In particular, the calculation of response functions of protons, electrons, and photons by using Monte-Carlo simulations, the identification algorithm based on a neural network trained with simulated data, and the calculation of fluxes from count rates are described. Some measurements performed in different facilities are presented. A part of these experimental tracks has been used to challenge the neural network previously trained with simulated data, to check the robustness of the algorithm. Proton, electron, and photon fluxes are presented and compared to the MAIRE model.