3D Imaging, based on X-ray and neutron technologies, is a non-destructive technique that provides 3D images of the internal structure of materials and components.

X-ray and neutron technologies are complementary and can be used to study different kinds of materials or different properties in materials.

Basically, neutrons are absorbed by light elements (i.e. with low atomic numbers) such as hydrogen, water, carbon etc., whereas X-ray are absorbed by heavy elements (i.e. with high atomic numbers) like metals for example.

These two pictures illustrate the complementarity of X-ray and neutron imaging.A neutron beam (top) easily penetrates the outer metal cabinet of the camera but is instead absorbed by the inner plastic parts, which appear dark.On the contrary the X-ray beam (bottom) is absorbed primarily by the metal parts.

Nanostructures

In-sito observation of diffraction patterns can give information about structure and porosity down to nanoscale (1-100 nm). Changes can be observed over time and as a function of for example concentration, temperature, pressure, low, pH and much more.

Examples of scattering experiments and the related information could be:

  • Small Angle X-ray Scattering (SAXS)
    • probes structures 1-100 nm
  • Powder Diffraction, including in-situ 
    • random or isotropic; nanoparticles 
    • poor crystalline order
  • Thin Films: random, textured, epitaxial
    • wide variety 
  • Surface Scattering/monolayers 
    • atomic structure at surface or interface
 

Trace elements and impurities

Neutron radiation can be used for trace element analysis. This can be done either by measuring the gamma radiation from activation: Prompt Gamma Activation Analysis (PGAA). Or by measuring the gamma radiation from the decay: Instrumental Neutron Activation (INA).

PGAA characteristics:

  • Short expornation times
  • Large sample can be measured
  • All elements are measured simultaneously
  • Sensitive down to ppm level
  • No sample preparation needed
  • More sensitive to light elements

INA characteristics:

  • Longer expornation times
  • Small samples needed
  • 4 different expornations, depending on element to be measured
  • Sensitive down to ppb level