New detectors aim to capture lighter forms of dark matter

New detectors aim to capture lighter forms of dark matter
by Clarence Oxford
Los Angeles CA (SPX) Sep 01, 2025

The search for elusive dark matter has gained a new tool, now operating deep within the French Alps. An international team, including Johns Hopkins University scientists, has deployed an ultrasensitive detector designed to probe particles far lighter than those targeted in decades of past experiments.

Researchers believe dark matter makes up about 85 percent of the universe, yet no direct laboratory evidence has been found. The new technology expands the search, either paving the way for the first detection or eliminating entire categories of theories that have remained untested.

"Dark matter is one of the most important ingredients that shape our universe and also one of the greatest cosmological mysteries," said Danielle Norcini, assistant professor of physics and astronomy at Johns Hopkins. "Our prevailing theories about the nature of dark matter aren't yielding results, even after decades of investigation. We need to broaden our search, and now we can."

Traditional dark matter detectors rely on heavier atoms such as xenon or argon, attempting to catch recoils when weakly interacting massive particles (WIMPs) collide with nuclei. But after forty years of searching, no such signals have appeared, suggesting that lighter, weaker particles may be the real culprits.

The new devices, called silicon skipper CCDs, can register signals from single electrons, enabling searches for dark matter similar in size to an electron rather than a nucleus. This shift allows scientists to pursue particles described as "WIMPier than the WIMPs."

To minimize interference, the instruments operate inside the Laboratoire Souterrain de Modane, located two kilometers underground in the French Alps. There, the surrounding rock shields cosmic rays, while layers of ancient lead and specially grown copper reduce background radiation.

"Trying to lock in on dark matter's signal is like trying to hear somebody whisper in a stadium full of people," Norcini explained. "While we haven't discovered dark matter yet, our results show that our detector works as designed, and we are starting to map out this unexplored region."

Following the successful proof-of-concept with eight skipper CCDs, the team plans to expand to 208 sensors. The scaled-up version, known as DAMIC-M, will become the most sensitive instrument dedicated to finding this lighter class of dark matter.

Research Report:Probing Benchmark Models of Hidden-Sector Dark Matter with DAMIC-M