Lab employees author X-ray imaging book

After three current and former Lawrence Livermore National Laboratory (LLNL) employees and a university professor found a need, they started down the long road to meet it.

When the LLNL trio -- physicist Harry Martz, retired engineer Clint Logan and retired computer scientist Dan Schneberk -- and a colleague surveyed scientific books on X-ray imaging, they discovered a glaring gap: Multiple books had been written about the use of X-ray imaging for medical applications, but virtually none addressed the subject of X-ray imaging for industrial and security applications.

So, in 2005, the four researchers undertook a decade-long odyssey to write a comprehensive book on the industrial, security and other applications of X-ray imaging. "X-ray Imaging: Fundamentals, Industrial Techniques and Applications," published last fall, is for senior undergraduate and first and second-year graduate students, as well as X-ray imaging professionals.

Peter Shull, an associate professor of engineering at Penn State University, is the fourth co-author.

The scientific treatise grew out of decades of research and practical experience building and using X-ray imaging and nondestructive evaluation systems at LLNL and studies in academia.

"There are many medical X-ray imaging textbooks, but very few X-ray imaging books that focus on non-destructive evaluation, industrial applications or security," said Martz, who serves as the director of the Lab’s Nondestructive Characterization Institute and is a Distinguished Member of the Technical Staff at LLNL.

"For the industrial world, there have not been any books addressing digital detectors and computed tomography," Logan added. "We saw that a lot of industrial research papers were published, but that there hadn’t been any books."

The foundation of the book was laid in 2002 when Martz and Logan penned a chapter on X-ray radiography for Shull’s book, "Nondestructive Evaluation: Theory, Techniques and Applications."

It went further in 2005 when Martz and Logan joined with Schneberk to teach a five-day UCLA extension class on X-ray imaging at the Lab’s Department of Applied Science near the Discovery Center.

"This is the culmination of our three careers at LLNL, with close to 100 years of research and development and practical applications," Martz said.

Martz, Logan and Schneberk worked together and with others for 15 to 20 years on a wide variety of scientific and engineering projects in the nondestructive evaluation section of the Lab’s Materials and Manufacturing Engineering Division, which was then part of Mechanical Engineering.

They built computed tomography systems and developed software for the acquisition, processing, reconstruction and analysis of images for work around the world. The trio analyzed an eclectic mix of materials and systems -- from electronic circuit boards and dinosaur eggs to nuclear weapons and components.

Their work encompassed the nondestructive assay of transuranic waste barrels; materials and assemblies for the Lab’s former R Program and the National Ignition Facility; work on explosives detection for the Department of Homeland Security; munitions analysis for the Department of Defense, and materials for NASA’s return to flight after the Columbia shuttle accident.

"Our work at LLNL involved a wide variety of materials and inspection requirements," Schneberk said. "We felt this put us in a unique position to describe and analyze the many applications for X-ray inspections.

"One of the goals of the book was to cover the full scope of X-ray inspection methods. For spatial resolution, we cover X-ray techniques of scales from nanometers to millimeters. For energy range, we reviewed 5 kilovolts to 15 million electron volts. For materials, our work covered carbon fibers to uranium.

"Across this range of inspections and inspection contexts, a number of different types of detectors are introduced, configured with or without collimation and used in combination with different object-detector motions. We felt there was no other book that included this kind of coverage," Schneberk said.

Published by CRC Press of Boca Raton, Florida, the book’s 17 chapters cover numerous technical areas, including the physics of X-ray and gamma-ray sources; simulation of radiation transport; types of radiation sources, such as X-ray tubes, electron accelerators and pulsed sources; radiation detectors; image quality, and a short discussion of neutron and proton imaging.

In addition, the authors discuss the application of modern imaging technologies across a broad spectrum, including X-ray imaging inspection of art objects and aerospace components; characterization of munitions; screening luggage and cargo for contraband special nuclear materials or explosives; additively manufactured parts, and in-service inspection of components to inform repair-or-retire decisions.

Logan retired from the Laboratory in 2001 after working as a mechanical engineer for 38 years. He still works on occasion at the Lab.

Schneberk retired in 2012 after working for about 30 years at LLNL, including the last two-thirds of his career in nondestructive evaluation.

Martz, who is considered an expert in explosives detection for the Department of Homeland Security, has worked at LLNL for nearly 31 years.

Part of the reason Martz wanted to write the book, he said, is because he thinks highly of the Laboratory, which has performed a large volume of work in X-ray inspections and computed tomography, and thought LLNL should be recognized.

"You don’t write a book like this for the money. You write it to make a contribution to the field," he said.

There were periods when writing and work on the book stopped for as long as two years -- and the threesome wondered if it would ever be completed.

"There were times when I didn’t think we’d finish, but Harry wouldn’t let me quit," Logan said.

And Logan wouldn’t let Schneberk quit.

"For me," said Schneberk, "the turning point was a couple of years ago at lunch with Clint. He said, ‘Dan, are we going to finish this? There is no other book out there like the one we are working on. Are you with me -- do you want to do this?’"

And they did.