Jan 2023: Research within the Nondestructive Characterization Institute at LLNL

Presentation Title: Research within the Nondestructive Characterization Institute at LLNL

Speaker: Harry Martz, Lawrence Livermore National Lab

Presentation Summary: The Nondestructive Characterization Institute (NCI) at LLNL performs research and development and applies cutting edge methods and technologies to characterize and inspect materials, parts, subassemblies, and assemblies of national security interest. For example, we need to inspect dense materials and objects, such as high atomic number, Ta-W and Pb-Sb alloys, advanced manufactured (AM), and traditionally manufactured parts and assemblies. These often require high-energy x-rays, exceeding 1 MeV, and sub-millimeter spatial resolution for characterization. Current high-energy x-ray systems offer limited flexibility in tuning the x-ray energy and spatial resolution. Current x-ray sources include bremsstrahlung tube heads that operate from 10 to 600 kV and accelerators that operate from 2 to 15 MV. These systems have spatial resolution on the order of 1 mm, which limits the features that can be observed. An alternative approach is to use an Inverse Compton Scattering (ICS) x-ray source (currently under development) to provide tunable keV to MeV quasi-monoenergetic x-rays and an x-ray focal spot size on the order of a micrometer, to obtain micrometer-scale spatial resolution images. Our research seeks to answer the question: can quasi-monochromatic x-ray sources fundamentally change the way x-ray non-destructive characterization (NDC) is carried out on these challenging materials, parts, and cargo? We performed CT scans of tungsten carbide and stainless steel phantoms using ICS x-rays produced by the BErkeley Lab Laser Accelerator Hundred TeraWatt (BELLA HTW) facility. Our reconstructed images have artifacts, but nevertheless demonstrate the potential of this ICS source. An overview of NCI and the BELLA HTW system used, results, lessons learned, and paths forward will be presented.

Speaker Bio: Harry Martz is the Director for Nondestructive Characterization Institute and a distinguished member of the technical staff at Lawrence Livermore National Laboratory, Livermore, CA. Harry is leading a team of scientists and engineers to research, develop, and apply nondestructive characterization methods to better understand material properties and inspection of components and assemblies. He has applied computed tomography (CT) to inspect one-millimeter sized laser targets, automobile and aircraft components, reactor-fuel tubes, new production reactor target particles, high explosives, explosive shaped charges, dinosaur eggs, concrete, and nondestructive radioactive assay of waste drum contents. Recent R&D efforts include CT imaging for conventional and homemade explosives detection in luggage and radiographic imaging of cargo to detect special nuclear materials and radiological dispersal devices. Dr. Martz has authored or co-authored over 300 papers. Harry and colleagues published a book titled X-ray Imaging: Fundamentals, Industrial Techniques and Applications. He has also served on several National Academy of Sciences Committees on Aviation Security and was the Chair of the Committee on Airport Passenger Screening: Backscatter X-Ray Machines. Harry has been co-chair of the Awareness and Localization of Explosives-Related Threats, Advanced Development for Security Applications and Advanced Developments Encompassing Processes and Technologies Workshops. Harry joined the Laboratory in 1986 as a Physicist to develop the area of X-ray imaging and proton energy loss computed tomography for the nondestructive inspection of materials, components, and assemblies. He received his M.S. and Ph.D. in Nuclear Physics/Inorganic Chemistry from Florida State University, and his B.S. in Chemistry from Siena Collage.