A team of undergraduate researchers at Texas Tech University is employing tools from high-energy physics to probe one of Ireland’s most iconic prehistoric structures: Queen Medb's Cairn.

Cairns are man-made piles or mounds of stones and were often built in prehistoric times. They were commonly used as burial monuments, boundary markers, or ceremonial structures. In places like Ireland and Scotland, large cairns, like the Queen Medb’s Cairn, were constructed to mark significant rituals or funeral sites.

Undergraduate researchers Michael O'Donnell and Odin Schneider, along with Nural Akchurin and Shuichi Kunori, professors in the Department of Physics and Astronomy, led much of the study’s development. 
The article “Queen Medb’s Cairn: A Feasibility Study in Muography,” was published online on October 9, 2025, in the Journal of Applied Physics (Vol. 138, Issue 14). Queen Medb’s Cairn is thousands of years old and has never been excavated, meaning any conventional excavation could cause irreversible damage, making non-destructive methods the only ethical and acceptable way to investigate its interior.

Their new study examines whether muon tomography, a non-invasive imaging technique that leverages naturally occurring cosmic-ray particles, can reveal the internal features of the large Neolithic burial monument on Knocknarea Mountain in County Sligo.

Muon tomography offers a promising scientific alternative. Muons are subatomic particles that constantly bombard Earth as a result of cosmic rays. Because they can pass through rock and dense structures, measuring the number of muons that pass through different parts of the cairn allows researchers to map density variations. This process can potentially reveal hidden chambers, passageways, or voids, and has previously been used to scan pyramids, volcanoes, and other large, dense structures.

O’Donnell, a second-year College of Arts & Sciences double-major in the Departments of Physics & Astronomy and Mathematics, said he came to Texas Tech specifically because he was interested in studying astrophysics.

“I said I was never going to change my major, and then two weeks in I changed it to higher energy physics and found a research group to be part of,” O’Donnel said. “It has turned out to be one of the best undergraduate research opportunities in Texas, in my opinion.”

The switch of his major, and the support he received from faculty to pursue undergraduate research, led O’Donnel to help revive the dormant cairn project after discovering its connection to Ireland, a country tied to his own heritage.

“I found this project had lost momentum,” O’Donnel said. “I asked Nural Akchurin about it. He told me that Odin and I could restart it.

Odin Schneider, who spent part of his youth in Germany and returned to Lubbock to attend Texas Tech, said joining the Advanced Particle Detector Laboratory (APD Lab) allowed him to learn about specialized simulation tools.

“The simulation structure is very niche to particle physics and has a lot of its quirks,” Schneider said. “You build the geometry yourself, and if anything overlaps, it crashes. Getting used to simulating particle physics in the field was a big part of the learning process.”

The published paper reports a comprehensive feasibility study. O’Donnel and Schneider built a 3D reconstruction of the cairn. They used particle-physics simulation tools, including GEANT4 and CRY, to model how cosmic muons would traverse the mound under various detector arrangements.

Their simulations indicate that muon tomography could reveal major internal features, such as hidden chambers or voids, if they exist. The proposed detector layout, capturing muon paths from multiple angles around the cairn, maximizes the technique’s sensitivity.

Notably, the data suggests that meaningful imaging could occur within archaeology-relevant timescales, meaning this is not just theoretically possible, but feasible and could be done without disturbing the monument. This approach preserves cultural heritage while expanding the scope of human history studies.

“This work demonstrates how particle physics tools can contribute to cultural heritage, archaeology, and Irish history,” O’Donnell said. “The feasibility is there. The next steps would be getting funding, building the detector and going to Ireland to set it up.”

The student researchers also incorporated emerging machine-learning techniques to improve the speed and accuracy of identifying potential features within the cairn. When paired with modern AI tools, these methods are becoming increasingly powerful in enhancing image recognition and refining muographic analysis.

O’Donnell and Schneider played a key role in applying these algorithms to the study, demonstrating how advanced computational approaches can accelerate data interpretation and strengthen the overall feasibility of using muography for archaeological investigation.

Through this interdisciplinary effort, Texas Tech positions itself as a leader at the frontier of archaeology and high-energy physics. These high-level undergraduate research opportunities affirm that From Here, It’s Possible™.

Read the published article and learn more about the research and these emerging researchers here: https://pubs.aip.org/aip/jap/article/138/14/144902/3367197/Queen-Medb-s-cairn-A-feasibility-study-in.

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