Powerful laser used to create the first images using muons

Superman was tricked. X-ray vision is not where it’s at. If yesterday’s comic book writers knew what we know today, the Man of Steel would have shot muons from his eyes to see through stone walls.

Firing the most powerful laser in the world in Romania Extreme Light Infrastructure Nuclear Physics (ELI-NP), a team of physicists generated a beam of high-energy particles called muons visualize an object through meters of concrete.

However grainy and lacking in detail, the “images” (featured in a paper available on the preprint website arXiv) represent a landmark advance in imaging technology that has applications in everything from security to mining.

Muons are electrons on steroids. These heavyweights are commonly generated when high-speed protons streak through space and collide with atoms in our upper atmosphere, forcing them to eject pairs of quarks called pions.

Pions quickly decay into muons, which in turn exist for a blink of an eye before decaying into their lighter-mass cousin (and some neutrinos).

Although their lives are short, muons that rain from above they survive long enough to reach the surface. Thanks in large part to their fleshy mass, they easily pierce the ground, slipping through dense layers of rock and penetrating much deeper than even the most powerful X-rays.

Archaeologists and engineers have exploited these cosmic showers for decades, using the glow of muons to search for signs of voids inside pyramids or mineral deposits deep underground.

Anyone who needs a muography quickly or needs images from the side is out of luck. The muons hit the surface at a fairly limited range of angles at a negligible rate of about one every square centimeter per second.

One way to artificially generate muons at practical distances is to use powerful lasers to rapidly accelerate electrons into waves of electromagnetism and smash them into a wall.

Last year, physicists at Porcelain, USAand the united kingdom used navigating electrons to produce muons, demonstrating that the technology was feasible.

Another international collaboration led by researchers at Lawrence Livermore National Laboratory and Colorado State University used the same method to create a flash of particles representing lead weights inside a truck. It’s unclear how many of those particles were muons, leaving the official “first photographs” open to some debate.

The ELI-NP’s 10 petawatt laser is not a flashlight. For a brief moment, its beam contains thousands of times the power of all the electrical grids on the planet. That flash propels the electrons in waves until they collide with a lead barricade.

To filter out as many non-muonic particles as possible, the researchers developed a novel and unique filter made of polyethylene sheets wrapped around paraffin blocks. From there, the relatively pure muon beam was allowed to radiate through a two-meter (six-foot) concrete wall and toward a series of detectors inside a van parked on the other side.

After capturing the shadow of a pile of lead blocks, the team considered it a victory and claimed to have the first official muonograph produced artificially with a laser.

It’s no Polaroid, but with some development, the principles could one day be used to develop a smaller transportable system that could peer through the iron hulls of rockets or shipping, the cores of rocky mountains, or the stone foundations of ancient structures with the ease of any superhero.

This research can be found on the preprint server, arXiv.

Fountain: Phys.org