Laser-Driven X-Ray Imaging for Internal Object Analysis

A research team led by Colorado State University achieved a significant milestone in 3D X-ray imaging technology. The study details the physics and engineering behind this new radiography imaging capability and explores how it could benefit various industries, including additive manufacturing and aerospace.

Using a small, laser-driven X-ray source, the researchers are the first to achieve high-resolution CT scans of the interior of a large, dense object: a gas turbine blade.

The project has been a collaborative effort involving researchers from CSU's Departments of Electrical and Computer Engineering, Physics, and Los Alamos National Laboratory, with additional involvement from AWE in the UK.

This demonstration is just the beginning. We are using the CSU-built ALEPH laser to generate extremely bright X-ray sources to do high-resolution X-ray radiography and CT. As we develop our new facility, our goal is to ramp this into something that can make a broad impact.

Reed Hollinger, Assistant Professor and Study Lead Author, ECE, Colorado State University

The team's method offers a fast, non-destructive way to examine the interior of complex systems, such as turbojet engines and rocket components. This new technique could greatly enhance quality control while preserving the integrity of 3D printed products as additive manufacturing continues to expand.

Next-Generation Laser-Driven Imaging

Industrial CT scanners are typically large, expensive, and produce images with millimeter-scale resolution. By using a laser to generate a much smaller X-ray source, the team can achieve significantly higher resolution without reducing the energy of the X-ray.

A small spot MeV X-ray source is the single largest lever that is potentially available for improving high resolution MeV X-ray imaging.

James Hunter, Los Alamos National Laboratory

Hunter worked with Hollinger on the study.

The technique, based on physics principles, accelerates an electron beam to a few million volts over a few microns of space—less than the width of a human hair—using a petawatt-class laser-focused to an intensity of 10²¹ Wcm^-2.

The electron beam collides with heavy atoms in the target, causing them to release X-rays. These X-rays are much more energetic than those produced by traditional hospital X-ray tubes, providing the necessary energy to penetrate thick materials, like the turbine blades in this study.

For perspective, the energy of a traditional hospital X-ray source is only tens of thousands of volts as opposed to our X-ray source, which is millions of volts.

Reed Hollinger, Assistant Professor and Study Lead Author, ECE, Colorado State University

Hollinger is a member of the Walter Scott, Jr. College of Engineering at Colorado State University.

The short duration of each X-ray pulse, only a few trillionths of a second, enables time-resolution radiography of objects moving at extremely high speeds.

“For example, we could one day capture high-resolution 3D images of the inside of a jet engine while it’s operating. Currently, there are no other X-ray sources that can do this,” said Hollinger. 

The group's work is part of a broader effort to use high-intensity laser sources for various applications, such as generating intense MeV X-rays, GeV electrons, and researching inertial fusion energy. These technologies are part of an initiative that academics aim to scale up with support from CSU.

Journal Reference:

Hollinger, R., et al. (2025) Laser-driven high-resolution MeV x-ray tomography. Optica. doi.org/10.1364/OPTICA.542536