Celebrating 70 Years of Muon Tomography

This year, the global scientific and technological community marks the 70th anniversary of the first application of Muon Tomography (MT).

The journey began on July 1, 1955, marking the start of a revolution that turned naturally occurring cosmic particles into powerful, non-destructive imaging tools. 

1955: The Birth of a New Science 

The concept of using cosmic rays to evaluate matter began two decades after the muon's discovery. The foundation of muon tomography was laid in 1955 by physicist E.P. George, an academic at the University of Sydney.

George conducted the first known field trace to measure the rock overburden in the Guthega-Munyang tunnel system, part of the hydroelectric power scheme in Australia's Snowy Mountains. By measuring the natural attenuation (or absorption) of muons, he demonstrated that subatomic particles could serve as a powerful, passive diagnostic tool for massive geological structures. This pioneering work established the first use of muon radiography.

From Pyramids to High-Tech Security to Infrastructure

Following George's initial success, the technique gained global renown with Nobel laureate Luis Alvarez's work in the late 1960s, using muography to search for hidden chambers within Egypt’s Pyramid of Khafre.

While early techniques relied on muon transmission (measuring absorption), the field advanced significantly with the development of modern Muon Scattering Tomography (MST). This technique tracks the trajectory of muons, allowing for the creation of high-resolution 3D images that clearly reveal hidden issues or items.

Today, muon tomography is an indispensable tool across numerous sectors:

• Infrastructure: Monitoring the health of critical infrastructure like bridges and tunnels to detect issues like voids, wire breaks and section loss in reinforcement

• Security & Border Control: Inspecting cargo containers for shielded nuclear materials or contraband.

• Mining & Geology: Mapping ore bodies underground and imaging the interiors of active volcanoes.

• Archaeology: Non-invasively scanning ancient monuments, such as pyramids and burial mounds, to discover hidden chambers and internal voids without causing structural damage.

Advancing Infrastructure Inspection

The modern application of muon tomography is rapidly transforming civil engineering. A key advancement in this area is the use of GScan’s Muon Flux Technology (MFT), which utilises AI-driven analysis of natural cosmic radiation to provide deep, non-destructive structural assessments. 

Muon Flux technology achieved a landmark moment when it was deployed on the Llanrhystud Bridge in 2025, becoming the UK's first operational bridge to be evaluated using this cutting-edge method. It was also used for the first time in 2025 to detect possible wire breaks in suspension bridge main cables. The first half-joint was also scanned by GScan’s MFT in 2025 - a milestone year in many ways!

 By penetrating deep into structures with remarkable accuracy, MFT enables engineers and asset managers to detect hidden defects, voids, and structural weaknesses with a clarity that traditional methods cannot match.

The leap from experimental physics to a reliable engineering tool was accelerated by the National Highways Structures Moonshot project, led by AkinsRealis and Jacobs. This ambitious initiative focused on analysing England's highway structures with hidden critical components which are difficult and expensive to inspect, such as post-tensioned bridges.

The Moonshot programme was instrumental in transitioning the technology from the development stage to the deployment-ready GScan systems used today. It provided the rigorous testing ground needed to prove that Muon Flux Technology could outperform traditional non-destructive testing (NDT) methods in complex, real-world conditions.

2025: The Year of Industrial-Scale Breakthrough

We have now reached a definitive "tipping point" in the history of the science. While the previous seven decades focused on proving the physics for different applications and developing the technology for commercial use, 2025 marks the year Muon Tomography transitioned into an industrial-scale solution.

Several key factors have converged to enable this global deployment:

• AI-Enhanced Processing: The integration of advanced AI models has made it possible to create true volumetric (3D) models tied to site coordinates.

• Hardware Scalability: GScan’s modern systems are now more cost-effective to produce, enabling simultaneous deployments across multiple international sites.

• Global Asset Management Integration: For the first time, muon data can now be formatted for CAD/BIM/GIS integration, enabling asset managers to overlay real-world structural data directly onto existing digital twins.

As Muon Tomography celebrates its 70th birthday, the technology continues to evolve rapidly. The focus has shifted from simple flux counting to sophisticated 3D reconstruction algorithms that resolve hidden details with increasing clarity and speed.

Companies like GScan are contributing to this next phase of development in infrastructure inspection with their state-of-the-art scanners combined with advanced AI to process cosmic data more efficiently. The collective effort across academia and industry ensures that the legacy established 70 years ago continues to yield transformative tools for the world's most critical inspection challenges.