Abstract
The radiation environment in space poses unique challenges to the successful operation of electronic components exposed to it. Hence, it is important to test the devices sufficiently before integrating them in space missions. Even better to do so already during their design phase. Likewise, radiation effects on electronics also represent reliability and availability threats for high-energy accelerator applications.
The work performed in the frame of this thesis focuses on the investigation of beams mimicking space and accelerator environments. Radiation such as Ultra-High Energy (UHE) heavy ions and Very High Energy (VHE) electrons play an important role in this context. Since UHE heavy ions are mostly present in the Galactic Cosmic Radiation (GCR) environment and electrons are mostly trapped around planets such as the Earth and Jupiter, their interaction with matter and the resulting radiation effects are of special interest.
Aspects such as nuclear fragmentation and energy deposition mechanisms are relevant when estimating the possible impact on electronic components of radiation present in space or on the ground. Hence, tests have been performed to study this response to the radiation exposure particle types in dedicated test facilities. During such experiments, the dosimetry and beam parameters must be in full control.
UHE heavy ion test campaigns and experiments with VHE electrons at CERN have served as an excellent opportunity to investigate the interaction with matter of various particle species and energies similar to the GCR and electron-rich environments in space, such as around Jupiter. Due to their high penetration depth, one of the advantages of UHE heavy ion beams at CERN is to test without decapsulation. Moreover, these beams offer the opportunity to work with particles of identical Linear Energy Transfer (LET) and energies to the ones in space. That is interesting, because on the contrary it is a well-established standard to perform radiation tests for space applications with low energy heavy ions.
With regards to high-energy electrons, the implications of an exponential increase in Single Event Effects (SEEs) connected to testing at a high instantaneous electron flux [1] and the resulting nuclear electron processes [2] need to be considered. These observations deserve to be characterised and understood, even if they might represent an experimental artefact.
For these reasons, the central research questions in this work are:
- Is testing with particles of the same LET, but different energy compared to the space environment representative enough?
- How can electron beams at CERN be used to test electronics for future space missions, which will be exposed to electron-rich environments? Are there non-linear effects related to high instantaneous intensities of electron fluxes by changing the charge density per pulse?
This work has contributed to the understanding of physical phenomena occurring in electronics caused by radiation present in space and in accelerators environments, such as fusion and nuclear fragmentation processes and energy deposition in different materials and volumes. Ground level experimental work in related particle beams, as well as Monte Carlo simulations tools like FLUKA have served for the investigations presented in this PhD thesis.