Dottorato in ENERGIA E AMBIENTE

Titolo della tesi: Radiometric impact assessments and shielding of CubeSat class satellites in interaction with orbital radiation fields and representativity of the calibration procedure and radiation damage tests in the ground facility

Abstract Using FLUKA and MCNP nuclear particle transport codes, support for radiation shielding design and assessing damage to aerospace components and systems has been developed. In order to make the method quantitative, it was necessary to face the representativeness of the damage tests conducted on the aerospace components and systems with accelerators, nuclear research reactors, and spontaneous decay sources by making parallels with the orbital sources obtained from the applications used in the design of missions. As the first step, a high-energy calibration of the codes has been executed comparing the simulation results obtained simulating the Galactic Cosmic Ray atmospheric shower with the measured fluxes and spectra of secondary cosmic neutrons from ground stations, obtaining an excellent agreement. The activity continued with the design of the payload radiation shield of the ABCS (Astro Bio CubeSat) satellite launched in the Van Allen belt in the summer of 2022. A further point of verification was the comparison between dose rates measured with the dosimeters integrated into the ABCS payload during the mission and the simulated ones, which appear to be in fair agreement paving the way for the design of a series of ground-based experiments to be performed in parallel on research accelerators and reactors, to quantify and unify equivalent damage measurements.