Laser-driven muon beams image through concrete for the first time

Overview

Updated 2 hours ago

In June, researchers at a Romanian laser facility fired the world's most powerful beam through a two-meter concrete wall and into a black van. The shadow it cast revealed a stack of lead blocks—the first image produced almost entirely by muons, particles created on demand by the laser.

Muons are electrons' heavier cousins, and they slip through dense materials like lead that block X-rays. If laser-driven muon sources can be refined and shrunk, inspectors could scan sealed containers for smuggled nuclear material, and archaeologists could map structures no light can reach.

Why it matters

Portable muon scanners could let customs officers see inside sealed lead containers and cut scan times from hours to minutes.

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Key Indicators

90%

Muon purity of laser-generated beam

About 90% of particles reaching the detectors were muons after filtering.

10 GeV

Electron energy reached at Berkeley Lab

Multi-billion-electron-volt electrons produced over a 30-centimeter acceleration distance.

30 cm

Electron acceleration distance

Compared with roughly a kilometer for a traditional accelerator.

2,000×

Laser peak power vs global grids

ELI-NP's laser briefly delivers more than 2,000 times the power of all the world's electrical grids combined.

Cosmic muons per minute per square centimeter

The scarce natural flux that makes cosmic-ray scanning too slow for busy ports.

Voices

Curated perspectives — historical figures and your fellow readers.

Ever wondered what historical figures would say about today's headlines?

People Involved

Domenico Doria

Lead physicist, ELI-NP muon imaging project

Leading the team that produced the first all-muon laser images

Madalina Dobre

Physicist, Horia Hulubei National Institute

Designed the filter that purified the muon beam

Brendan Reagan

Physicist, Colorado State University

Led earlier single-pulse imaging experiment

Sarah Barnes

Physicist, German Aerospace Center

Building security prototypes through the SilentBorder program

Davide Terzani

Physicist, Lawrence Berkeley National Laboratory

Reported compact laser-driven muon source

Organizations Involved

Extreme Light Infrastructure Nuclear Physics (ELI-NP)

Research Facility

Host of the world's most powerful laser; produced first all-muon images

A laser research facility outside Bucharest, Romania, whose laser briefly delivers more than 2,000 times the power of the global electricity grid.

Colorado State University Department of Atmospheric Science

University Research Lab

Demonstrated earlier single-pulse imaging with mixed particle beam

University lab that generated a single-pulse laser particle beam imaging a lead object inside a truck.

Lawrence Berkeley National Laboratory

Federal Research Laboratory

Demonstrated compact laser-driven accelerator for muon production

U.S. lab that compressed electron acceleration to 30 centimeters while reaching 10 GeV energies.

SilentBorder

EU-Funded Research Program

Developing muon scanning prototypes for border security

European Union program building muon scanners to inspect cargo for smuggled nuclear materials.

Timeline

August 2022 September 2026

5 events Latest: Yesterday

Tap a bar to jump to that date

September 2026
First all-muon laser images released
Latest Publication

ELI-NP preprint shows shadows made almost entirely by muons, roughly 90% purity.
Yesterday
June 2026
ELI-NP laser sends beam through concrete wall
Experiment

World's most powerful laser generates a beam passing through a 2-meter wall into a van.
June 1st, 2026
March 2026
Colorado State images through truck with laser pulse
Research

Single pulse images a lead object in a truck; beam mixes muons, pions, neutrons.
March 1st, 2026
October 2025
Berkeley Lab reports compact laser-driven muon source
Research

Electrons accelerate over 30 centimeters to 10 GeV, producing multi-GeV muons.
October 8th, 2025
August 2022
Muon tomography images nuclear reactor in 3D
Research

Cosmic-ray muons reconstruct a reactor interior noninvasively, but acquisition takes days per projection.
August 1st, 2022

Scenarios

Muon scanners deployed at a working port or border crossing

Possible Resolves by Sep 25, 2030

Discussed by: Sarah Barnes and the EU-funded SilentBorder program

SilentBorder moves from prototypes to a field trial at an operational customs site. Laser-driven sources deliver roughly 10,000 times more muons than cosmic rays and steer the beam, so scan times drop from hours to minutes. A successful trial on real cargo would mark the first operational use of artificial muon scanning.

Commercial laser-driven muon source hits the market

Possible Resolves by Sep 25, 2029

Discussed by: Barnes' German commercial partner, medical and industrial firms

A company announces a commercial product generating muons via laser-driven plasma acceleration. Target uses include rocket engine evaluation, medical imaging, and security scanning. The product would need portable lasers and better detectors, both named by researchers as current gaps.

Technology stays in the lab through 2030

Unlikely Resolves by End of 2030

Discussed by: Researchers citing laser portability and detector limits

Current lasers are facility-scale, not portable, and detectors need improvement. If laser miniaturization and detector development lag, the technique remains a lab demonstration despite proven physics. The science is established, but engineering hurdles could delay real-world use past the decade.

Historical Context

3 moments from history that rhyme with this story — and how they unfolded.

November 1895 – 1896

Röntgen's X-rays (1895-1896)

In November 1895, physicist Wilhelm Röntgen discovered X-rays in a Würzburg lab, finding they could pass through flesh and cast bone shadows on photographic plates. Within a year, surgeons used them to locate bullets and bone fragments.

Then

Medical imaging transformed within months of discovery.

Now

X-rays became a standard medical tool, with portable field units reaching battlefields in World War I, about two decades after discovery.

Why this matters now

Like X-rays, muons are a newly harnessed penetrating radiation. History suggests portable field deployment takes years, not months.

1967 – 1970

Alvarez's pyramid muography (1967-1970)

Physicist Luis Alvarez and colleagues placed muon detectors in a chamber beneath the Chephren pyramid in Egypt, using cosmic-ray muons to search for hidden burial chambers. The team reported results in 1969.

Then

No hidden chambers were found, but cosmic-ray muography proved workable for large structures.

Now

Muon tomography grew into a standard tool for volcanology, archaeology, and nuclear reactor inspection.

Why this matters now

Cosmic-ray muons arrive at just one per minute per square centimeter, so scans take days. Artificial beams remove that limit.

August 2022

3D reactor imaging with cosmic muons (2022)

Researchers used cosmic-ray muons to image a full nuclear reactor in 3D, reconstructing its interior without opening it. Even with days of data per projection, the method revealed the reactor's main components.

Then

Demonstrated muography for nuclear safety and decommissioning.

Now

Showed what muon data can reveal about dense industrial structures.

Why this matters now

The technique worked, but slowly. Laser-driven muon sources aim to compress days of acquisition into a single shot.