Students built a dark matter detector and set new experimental boundaries

A compact experiment at the University of Hamburg searched for axions, one of the main candidates for dark matter, and showed that even small arrays can contribute to particle physics.

Modern cosmology is often associated with large observatories, complex instruments, global collaborations, and lots of money. However, progress can still be made through smaller, more flexible efforts, led by young researchers and supported by institutional resources and creative problem-solving, including in the ongoing search for dark matter.

In a study recently published in JCAP, a team of graduate students at the University of Hamburg designed and built a vacuum detector to search for axions, a potential leading dark matter candidate. Despite limited resources, they were able to establish new experimental constraints on the properties of axions, showing that even compact experiments can still contribute to one of the biggest open questions in physics.  

Searching for dark matter

"The advantage of working with dark matter, or axions, is that we expect it to be present everywhere in our galaxy," said Agit Akgomus, the study's first author. "So, in effect, no matter where you do the experiment, there is dark matter at hand that you can experiment on."

The team used its own money to build the experimental setup, starting with a resonant cavity made of highly conductive materials, along with electronics, cables, mounts, and measurement instruments. “The detector we built is essentially the simplest version of a dark matter cavity detector,” says Nabil Salama, one of the study’s authors.

They also relied on existing infrastructure and equipment provided by the university, and collaborated with other groups rather than building everything from scratch. They then tested, calibrated, and operated the system to collect data.

"We have reduced very complex experiments to their basic components," says Selma. "The result is a less sensitive array, limited to a small search window, but still capable of generating new scientific data."

No signal found, new restrictions set

"To search for axions, you need to test a wide range of possible parameters," explains Ekgomos. "Our experiment only covers a small area, with limited sensitivity, but it still helps narrow down the possibilities. To actually find the particle, you need much larger experiments or many different experiments, each testing a specific area."

After they finished collecting data, the team didn't detect any signal related to axions. This isn't a negative result because it provides important constraints. It allows scientists to rule out axions with certain properties in the mass range being tested, especially those that interact more strongly with photons. This helps refine the search and informs future experiments.

During the peer review, one of the reviewers pointed out an intriguing possibility, notes Selma. Once axions are discovered and their properties, especially their mass, are clarified, similar experiments could become much more accessible and even suitable for teaching laboratories. “We’ve been told that arrays like ours could one day become standard lab experiments for students,” Selma says. “In a way, we may have already anticipated this future, and we’ve shown that it’s already possible to build and run such an experiment on a small scale.”

DOI: 10.1088/1475-7516/2026/04/054

More of the topic in Hayadan:

• The scientists of the "Xenon 1 Ton" experiment identified a larger than expected amount of events that may indicate the existence of new physics
• According to a new theory, we've been looking for dark matter the wrong way.
• Dark dwarfs lurk in the center of the galaxy – a clue to the nature of dark matter
• Probing in the dark for dark matter
• The dark matter in the universe has a long life span