Evaluation of the neutron spectrum at flight altitude with Geant4 using different parameterizations.

Cosmic-ray-induced particles at flight altitude present an increasing concern because of the development of aircraft with high maximum cruising altitude (higher than 40 000 ft) and because of the miniaturisation of and increase in the amount of embedded electronic systems. There are different codes used to estimate the radiation field through the atmosphere, using different approaches and Monte Carlo methods. This work aims to evaluate the influence on the neutron spectra at ground and flight altitude of the parameterizations employed to describe spallation reactions and the density profile of the atmosphere. The results show that different versions of Geant4 and the data driven models used significantly change the neutron fluence rate and the ambient dose equivalent rate. The results show that the different atmospheric density profiles considered do not significantly change the neutron spectra. In this work, we also present comparisons with onboard and ground level measurements.