Dual mode shielding against space radiation using superconductive enhanced composites [AEGIS - Advanced Exploration Guard In Space]

Recent advancements in space technology have brought humanity closer to achieving one of its most ambitious goals -manned space exploration. Despite this promising progress, the challenge of mitigating health threats posed by space radiation remains (Durante et al., 2008). Thus, beyond the terrestrial magnetic field, ensuring the safety of humans and electronics engaged in extraterrestrial activity has been a compelling research area. This project addresses the critical need for innovative materials to effectively protect human health and essential equipment during extraterrestrial activities, marking a pivotal step toward the actualisation of the plan of manned space exploration.

The extensive range of ionising radiation encountered in space encompasses Solar Particle Events (SPEs) and Galactic Cosmic Rays (GCRs) originating from the sun and outside the solar system. These two radiation sources exhibit distinct energy spectra and radiation compositions, necessitating separate consideration. SPE is characterised by abrupt and extremely intense bursts of low-energy (1-100 MeV) particles, primarily protons and a minor presence of alpha particles (helium ions). On the other hand, GCRs consist of a continuous dose of ionising particles with energy on the order of magnitude of 1 GeV, penetrating deeply throughout the solar system. Approximately 87% of GCRs are protons, followed by 12% of alpha particles and 1% of high atomic number (Z>2) and energy particles (HZE) devoid of all orbiting electrons (Simpson, 1983; George et al., 2009).

Various shielding methods have been explored to address the challenges posed by space radiation and can broadly categorised as active and passive shielding. Active shielding utilises an external energy source to create an electromagnetic field around the habitable zone of the spacecraft, deflecting incoming charged particles. Following the discovery of the superconductivity phenomenon in 1911 (Van Delft and Kes, 2010), the application of superconducting magnets, which, through their unique ability to generate strong magnetic fields and exhibit zero electrical resistance, has emerged as a transformative approach in the field of active shielding, with the first proposal in the 1960s (Levy and French, 1968). On the other hand, passive shielding relies on static materials as a barrier, able to absorb and/or attenuate both charged and uncharged radiation that is unaffected by the Coulomb forces. Composite materials containing low-Z constituents and enriched with high-hydrogen content have gained recognition through their improved structural and radiation shielding performance (e.g., Evans et al., 2018; Kaul et al., 2004), especially against radiation poses charge neutrality.

Building upon the combined principles of both shielding methods (e.g., Al Zaman and Monira, 2023), this project draws inspiration from the concept of superconductive-enhanced composite materials. This innovative approach integrates active shielding, leveraging superconducting additives, with passive shielding using matrix constituents within a family of well-characterised polybenzoxazine resins (Kong et al., 2023; He et al., 2024). The primary objective of this project is to alleviate the reliance on massive superconducting magnets, considering the overall mass, cost and performance of the superconductive-enhanced composite material in the context of space radiation shielding applications.

The further aims of this project are: (i) to gain an understanding of the requirements of the chosen superconductor based on its scale and morphology as an additive in composite, (ii) to characterise the improved interfacial interaction between superconductor and matrix constituent, (iii) to demonstrate the radiation shielding efficiency of this innovative material, possessing passive and active shielding approach.

There are seven principal groups of beneficiaries for our new EPSRC Centre for Doctoral Training in Composites Science, Engineering, and Manufacturing.

1. Collaborating companies and organisations, who will gain privileged access to the unique concentration of research training and skills available within the CDT, through active participation in doctoral research projects. In the Centre we will explore innovative ideas, in conjunction with industrial partners, international partners, and other associated groups (CLF, Catapults). Showcase events, such as our annual conference, will offer opportunities to a much broader spectrum of potentially collaborating companies and other organisations. The supporting companies will benefit from cross-sector learning opportunities and

- specific innovations within their sponsored project that make a significant impact on the company;
- increased collaboration with academia;
- the development of blue-skies and long-term research at a lowered risk.

2. Early-stage investors, who will gain access to commercial opportunities that have been validated through proof-of-concept, through our NCC-led technology pull-through programme.

3. Academics within Bristol, across a diverse range of disciplines, and at other universities associated with Bristol through the Manufacturing Hub, will benefit from collaborative research and exploitation opportunities in our CDT. International visits made possible by the Centre will undoubtedly lead to a wider spectrum of research training and exploitation collaborations.

4. Research students will establish their reputations as part of the CDT. Training and experiences within the Centre will increase their awareness of wider and contextually important issues, such as IP identification, commercialisation opportunities, and engagement with the public.

5. Students at the partner universities (SFI - Limerick) and other institutions, who will benefit from the collaborative training environment through the technologically relevant feedback from commercial stakeholder organisations.

6. The University of Bristol will enhance their international profile in composites. In addition to the immediate gains such as high quality academic publications and conference presentations during the course of the Centre, the University gains from the collaboration with industry that will continue long after the participants graduate. This is shown by the

a) Follow-on research activities in related areas.
b) Willingness of past graduates to:

i) Act as advocates for the CDT through our alumni association;
ii) Participate in the Advisory Board of our proposed CDT;
iii) Act as mentors to current doctoral students.

7. Citizens of the UK. We have identified key fields in composites science, engineering and manufacturing technology which are of current strategic importance to the country and will demonstrate the route by which these fields will impact our lives. Our current CDTs have shown considerable impact on industry (e.g. Rolls Royce). Our proposed centre will continue to give this benefit. We have built activities into the CDT programme to develop wider competences of the students in:

a) Communication - presentations, videos, journal paper, workshops;
b) Exploitation - business plans and exploitation routes for research;
c) Public Understanding - science ambassador, schools events, website.