- Artificial muon beams can penetrate dense materials, providing non-destructive inspection.
- Laser-driven technology can generate controllable particle streams on demand, accelerating imaging speed.
- Scan time reduced from half a year to minutes, improving practicality.
- Technology applicable to bridge inspection and volcanic activity prediction.
Superman's X-ray vision isn't so super after all. X-rays are suited for seeing through thin objects or medical scans, but thick concrete walls and dense lead barriers block X-rays completely. Physicists have found a solution: using muon particles, which are produced by powerful lasers and can easily penetrate dense materials that block X-rays. A research team from Romania, working at the Extreme Light Infrastructure – Nuclear Physics (ELI-NP) facility and led by Mădălina Dobre, has for the first time successfully imaged an object using a laser-driven artificial muon beam.
Artificial muon beams possess tunable properties, offering significant practical value for scanning dense objects that block other imaging techniques.
Next-generation scanning technology uses naturally occurring cosmic muons that penetrate Earth's upper atmosphere and reach deep into solid structures, enabling non-destructive hidden internal imaging. Previously, 'muon imaging' has mapped hidden internal structures, such as the secret chamber discovered inside the Great Pyramid of Giza in 2023. However, scan times remain impractically slow because naturally arriving cosmic particles trickle in at an extremely low rate. Current facilities use conventional particle accelerators to produce low-energy beams, while high-energy muons require laser-driven field acceleration of electrons interacting with solid targets.
Breakthrough imaging technology
Researchers at Romania's Horia Hulubei National Institute have solved the speed challenge, producing images using an artificial muon beam for the first time. Their laser-driven technology can generate controllable particle streams on demand, opening the door to fast, reliable practical imaging.
The Dobre team used the high-power laser at Romania's ELI-NP facility to produce the first image dominated by artificial laser-driven muons. The laser accelerates electrons through a gas, directs them at a solid target, creating light pulses that generate muon pairs. After filtering unwanted particles using plastic, paraffin, and a concrete wall 2 meters thick, a detector inside a truck recorded the shadow of a stack of lead bricks. Comparing these measurements with computer simulations confirmed that approximately 90% of the detected high-energy particles were muons consistent with the source model.
"By comparing the data with Monte Carlo simulations, we confirmed that the measured beam profile and object imaging are consistent with artificial muons of several GeV in energy. To our knowledge, this represents the first demonstration of imaging dominated by artificial laser-driven muons," the team wrote in a preprint research paper.
Scan time drastically reduced
The facility's initial on-demand deep-scan images are not yet sharp. They appear grainy, low-resolution, more like rough shadows than high-definition scans. Yet the proof of concept changes everything. Natural cosmic-ray muon imaging yields only about 1 muon per square centimeter per second, while laser-driven pulses can produce millions of particles in an instant, drastically reducing scan time. On-demand generation of focused muon beams cuts scan time from half a year to minutes. Future versions could allow engineers to scan aging bridges, help geologists map underground mineral deposits, and enable border inspectors to detect heavily shielded nuclear materials hidden deep inside shipping containers.
Volcanologists could also use the technology to map internal magma chambers and lava tubes to help predict eruptions.
Application potential of laser-driven muon technology
The use of laser-driven muon beam technology brings revolutionary progress to material inspection, particularly in non-destructive imaging. This technology not only rapidly generates high-energy particle streams but also significantly shortens scan times, thereby improving inspection efficiency. In the future, the application scope of this technology will expand to bridge safety inspection, underground resource exploration, and volcanic activity monitoring, among other fields, holding significant importance for safeguarding public safety and resource management.