CT results using an inverse Compton x-ray source

Abstract

Nondestructive characterization is often carried out on dense materials and objects, such as cargo, and high atomic number advanced manufactured, 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. The MV systems have spatial resolution on the order of a millimeter which limits the features that can be observed. An alternative approach is to use an inverse Compton scattering (ICS) x-ray source with a linear plasma accelerator (LPA). This is a powerful emerging technology that can provide tunable keV to MeV, quasi-monoenergetic x-rays, and a focal spot size on the order of a micrometer. Our research seeks to answer the question: can ICS x-ray sources fundamentally change the way x-ray non-destructive characterization (NDC) is carried out on these challenging parts, assemblies, and cargo? We performed the first CT scans using the Berkeley Lab Laser Accelerator Hundred TeraWatt (BELLA HTW) ICS x-ray source. We scanned parts of tungsten carbide and steel. Our reconstructed images, although they have artifacts, demonstrate the potential of the LPA-ICS source to image challenging objects. We will discuss the system used, results, lessons learned and paths forward.

DOI: https://doi.org/10.1117/12.2665210