Single Event Effects in Ground Level Infrastructure

Objectives are stated in the previous section and are further elaborated in the Case for Support. The impact on project partners will be an improved understanding of the phenomenon of single event effects at ground level and the risk from an ESW event. This topic has hitherto focused on the quiescent background galactic cosmic ray environment, with very little attention paid to enhancements during space weather events. By reviewing the likelihood and potential impact of these events, the project will raise awareness of the topic within the partner organisations and, in due course, within the wider industries in which they operate. The main outcome will be a risk assessment of the vulnerability of ground-level electronic systems to SEE during an ESW event. SEE rates and failure probabilities will be calculated and used to determine what (if any) mitigation protocols are required to reduce the risk. Industry partners will be able to reduce the vulnerability of their systems using a variety of methods, including improving their procurement of electronic components based on resilience criteria and increasing failure tolerance through system design. The results may also be used to evaluate the need for retrofitting resilience measures to existing systems, though this is a consideration for the partners alone and the project will not make unilateral recommendations in this regard.

This work will influence the operational and strategic decisions of partner organisations which will depend on the results of the risk assessment. This is extremely hard to predict or pre-empt given the paucity of prior work in this area. In this instance historical experience is a poor guide to future vulnerability. The evolution of microelectronics technology, particularly the miniaturisation and ever-increasing complexity of components, means that the goal posts of susceptibility to radiation effects are forever moving. Compounding this uncertainty is the fact that the largest recorded GLEs (which are in any case by no means representative of a worst case scenario over the long term) occurred predominantly in the 1940s and 1950s, long before the era of miniaturised advanced technology. Thus it is the case that not only have critical systems not been tested in worst case conditions, they have not even experienced the type of relatively benign enhancement that might be expected on average every ten or twenty years. The absence of acute effects in the experience of ground level microelectronics could potentially have given a false impression about the resilience of critical systems to the natural hazards of space weather. The key benefit to partners from this work is, therefore, the ability to assess resilience to SEE in a rigorous quantitative manner, based on state-of-the-art knowledge of both the natural environment and technological vulnerability.

The outcomes will be:
1. Definition of a ground-level radiation environment during an ESW event
2. Assessemnt of the vulnerability of microelectronic components to thermal and high-energy neutrons
3. Quantification of single event effect rates and failure probabilities in a range of scenarios based on different assumptions regarding location, shielding, component type, etc.
4. Exploration of mitigation strategies: ranging from simple (and possibly existing) error detection and correction, to a scoping study of more advanced strategies such as procuring radiation hardened components or screening using ground test facilities
5. Recommendations for best practice in use of electronics in critical infrastructure