Cosmic rays continually bombard the Earth, producing secondary particles such as neutrons, muons, and gamma rays. These particles interact with matter in ways that can affect rare-event physics experiments, but they can also be harnessed in novel applications such as environmental monitoring.

In this project, the student will use the Geant4 Monte Carlo toolkit to study cosmic-ray interactions in:

• NaI(Tl) crystals, as used in the SABRE dark matter experiment, to quantify neutron- and muon-induced backgrounds and hence improve the dark matter detection sensitivity.
• Gas time projection chambers (TPCs), a common technology in next-generation dark matter detectors, to explore track signatures from cosmic-ray secondaries.
• Soil, an environmental medium where cosmic-ray neutrons can generate gamma rays. These signals may be used for non-destructive monitoring of soil composition and carbon content, offering potential applications in agriculture, mining and climate science.

Simulations will employ the CRY (Cosmic-Ray Shower Library) to generate realistic surface cosmic-ray fluxes, and the resulting detector signals will be analysed using ROOT and Python.

This project provides an opportunity to explore the broad impact of cosmic-ray interactions — from fundamental physics searches for dark matter to real-world applications in environmental science — while developing valuable skills in computational modelling and radiation transport.

Students should have a background in physics, computational science, or related fields. Prior experience with programming (C, C++ or Python) is helpful, and an interest in Monte Carlo simulations or environmental applications of nuclear physics will be an advantage.