X-ray Polarization as a Diagnostic Tool for Solar Flare Physics

About the Project

Solar flares represent explosive releases of magnetic energy in the Sun's atmosphere and are crucial components of space weather. Despite decades of research, fundamental questions about how magnetic energy converts to kinetic energy during flares remain unanswered. This PhD project addresses a critical gap in solar physics by investigating X-ray polarization, a powerful but previously underutilized diagnostic tool, to understand flare magnetic topology, energy release mechanisms, and electron acceleration and transport processes.

While solar physicists have extensively used X-ray timing, imaging, and spectroscopy to study flares, X-ray polarimetry represents the fourth observable that has been largely missing from our toolkit. Recent astrophysics missions like the Imaging X-ray Polarimetry Explorer (IXPE) demonstrate the technology's power, yet solar flare X-ray polarization measurements remain scarce and uncertain. This project aims to change that paradigm.

X-ray polarization provides two key observables known as the degree of polarization (DOP) and polarization angle (Ψ). The DOP reveals information about electron directivity, how electrons are distributed with respect to magnetic field lines, which constrains acceleration mechanisms. Strongly beamed electrons produce high DOP, with different patterns corresponding to different acceleration processes. Meanwhile, polarization angle Ψ relates to magnetic field orientation, potentially revealing magnetic structures near flare reconnection sites and how energy propagates through flare loops.

During the project, you will comprehensively investigate X-ray polarization as a diagnostic for solar flare energy release, magnetic configuration, and electron acceleration and transport. Through advanced modelling, you will demonstrate to the solar community how this missing tool can revolutionize our understanding of flares.

Your models will output all X-ray observables tunable to current and future missions, including NASA's PADRE CubeSat (launched 2025) and the proposed CUSP mission. There is opportunity to translate existing Interactive Data Language (IDL) codes into more accessible Python and parallel C++ versions, creating open-source software that clearly demonstrates X-ray polarimetry's diagnostic potential.

Additionally, your project will start after the opening of Northumbria University's new North East Space Skills and Technology (NESST) centre, a £50 million facility for space technology development. Working with space technology experts, there may be opportunity to explore whether CubeSats can perform high-resolution X-ray polarization spectroscopy, laying groundwork for affordable future missions, with the outputs of your work directly contributing to providing which technology is needed.

This project addresses key questions in astrophysics and plasma physics regarding magnetic energy transfer, particle acceleration, and electromagnetic emission interpretation. You will gain expertise in advanced computational modelling, X-ray physics, software development, and space technology, skills highly valued in both academic and industrial sectors, positioning you at the forefront of an emerging area in solar physics while providing an opportunity to contribute to UK leadership in space technology development.

Eligibility Requirements:

• Academic excellence i.e. 2:1 (or equivalent GPA from non-UK universities with preference for 1st class honours); or a Masters (preference for Merit or above); or APEL evidence of substantial practitioner achievement.
• Appropriate IELTS score, if required.
• Applicants cannot apply if they are already a PhD holder or if currently engaged in Doctoral study at Northumbria or elsewhere.
• Must be able to commit to campus-based full-time or part-time study.

To be classed as a Home student, candidates must:

• Be a UK National (meeting residency requirements), or
• have settled status, or
• have pre-settled status (meeting residency requirements), or
• have indefinite leave to remain or enter.

If a candidate does not meet the criteria above, they would be classed as an International student.

For further details on how to apply see https://www.northumbria.ac.uk/research/postgraduate-research-degrees/how-to-apply/

In your application, please make sure to include the advert reference (e.g. STFC26/...).

Deadline for applications: 1st June 2026

Start date of course: 1st October 2026

Funding Notes

This studentship is available to Home students and includes a full stipend at UKRI rates (for 2025/26 FT study this is £20,780 per year) and full tuition fees. Studentships are also available for Home applicants who wish to study part-time over 5 years (0.6 FTE, stipend £12,542 per year and full tuition fees) in combination with work or personal responsibilities).