Experimental and Simulation Study of Neutron-Induced Single Event Effects in Accelerator Environment and Implications on Qualification Approach

Electronic components and systems operating in the Large Hadron Collider (LHC) accel- erator at CERN are subjected to a mixed-field radiation environment, mainly composed of neutrons with energies ranging from thermal up to a few GeV. This thesis aims at determining the impact of thermal and intermediate energy neutrons (0.2-20 MeV) with respect to highly energetic particles on the Single Event Upset (SEU) and Latch-up (SEL) rates induced in ad- vanced Commercial-Off-The-Shelf (COTS) components, typically used in accelerator systems. The radiation environments of several locations in the accelerator are described, character- ized and compared to the ground level and atmospheric spectra at varying altitude. Inelastic and elastic nuclear processes through which neutrons of different energies induce Single Event Effects (SEEs) are extensively studied through Monte Carlo simulations, in terms of produced secondaries and their properties. Electronic components are experimentally characterized in monoenergetic and spallation facilities, and the SEE cross sections benchmarked with Monte Carlo simulations, where the energy deposition is associated with the SEE probability. From these studies, the SEE rate is estimated for accelerator and atmospheric applications and put in the context of the qualification approaches at component and system level used in these environments. The qualification implications are derived from the combined simulation and experimental study, in order to determine the approach for quantifying the thermal and intermediate energy neutron contributions. Several solutions are proposed aiming towards a radiation hardness assurance (RHA) methodology based on mixed-field and monoenergetic experimental results, besides the consolidated knowledge of the operational environments and the associated effects.