26th Australian Institute of Physics Congress and the Australian and New Zealand Conference on Optics and Photonics

From the cosmos to cancer therapy: untangling complex low-energy nuclear reactions

Not scheduled

20m

Belinda Hutchinson Building (The University of Sydney )

Contributed Oral AIP | Nuclear and Particle Physics (NUPP)

Speaker

Edward Simpson (Australian National University)

Description

Low-energy nuclear reactions are the fundamental process that underpins many applications of nuclear science, from the production of life-saving radioisotopes to the origins of the elements in the universe. These applications require comprehensive information about nuclear reaction probabilities, via angular-differential cross sections, as a function of the collision energy.

The reactions are often complex, exhibiting resonance structures that can change reaction probabilities by orders of magnitude for small changes in energy. These resonances interfere and increasingly overlap as the collision energy increases, and disentangling their contributions to reaction processes is a significant challenge. Ab-initio predictions of resonance properties are, in general, not possible and they must be deduced from experimental measurements. This can be done using phenomenological R-matrix theory but the process is both labor and computationally intensive. Some cases cannot be tackled with current approaches, limiting foundational science and potential applications.

In this talk, I will give an overview of low energy nuclear reactions and discuss recent work to develop more efficient approaches to R-matrix analysis of them. We have developed a new phenomenological R-matrix code which has been designed to allow the user to adjust resonance parameters and understand the impact on cross sections in real time, greatly improving productivity. Novel features of this code and ongoing work to integrate machine-learning-based models to further accelerate the analysis will be discussed.

We will also present recent analysis of the $^{11}$B(p,$\alpha$)$^{8}$Be reaction, which proceeds via resonances in $^{12}$C. The reaction is highly endothermic ($Q$ = 8.590 MeV) and does not produce neutrons, making it of interest for future fusion power reactors. Further, as the reaction produces three short-range $\alpha$-particles, it has potential use for dose enhancement in proton-therapy for hard-to-treat cancers, by using boron as a radiosensitizer in the target tissue (Proton Boron Capture Therapy).