Neutron Imaging

Neutron radiography and computed tomography of biological materials with complex geometries

Neutron imaging of water uptake under stress.

Water uptake under stress. Neutron radiography of a black cottonwood (Populus trichocarpa) planted in sand enabled examination of differences in water uptake by old and new plant roots following recovery from extreme drought stress. [Reprinted by permission of Springer Nature from Dhiman I., et al. 2017. "Quantifying root water extraction after drought recovery using sub-mm in situ empirical data," Plant and Soil 424, 1–17. DOI: 10.1007/s11104-017-3408-5. Copyright 2017.]

Neutron imaging takes advantage of hydrogen/deuterium contrast and the nondestructive, high penetrating power of neutrons to study structures in a wide range of hierarchical and complex materials of biological relevance. Image resolution ranges from ~10 to 50 µm. Applications include studying plant-plant and plant-fungal interactions, soil pore structure and voids under environmentally relevant conditions, fluid transport and interactions in porous media such as the rhizosphere, and cavitation and gas embolism in plant-soil-groundwater systems. Neutron imaging includes both neutron radiography and neutron computed tomography.

Neutron imaging of wheat roots

Neutron imaging of roots. A wheat root system in a soil matrix imaged using neutron tomography. [Courtesy Oak Ridge National Laboratory]

Key Features of Neutron Imaging

  • Spatial resolution of 10 to 50 µm
  • High-penetrating and non-destructive
  • Hydrogen/deuterium isotope contrast
  • Accommodates versatile sample types including organisms, soil, rock, and experimental devices
  • Boron, lithium, or gadolinium contrast agents

BER Researchers Use Neutron Imaging to Study:

  • Water uptake by root systems
  • Water transport in soils
  • Soil structure
  • Rhizosphere water dynamics
  • Adaptation of root systems in the presence of pollutants
  • Root behavior in extreme environments (e.g., drought)
  • Belowground root system response to climate change

See more examples in Science Highlights

Sample Considerations

  • Soil is preferably pure sand (SiO2) and devoid of organic matter (increased opacity to neutrons).
  • Samples should be transplanted from soil to sand around one week prior to neutron imaging experiments.
  • Soil should not be watered prior to imaging experiments (increased opacity to neutrons).
  • Beam thickness is determined by the amount of water in the chamber.
  • A neutron-transparent chamber such as aluminum or quartz should be utilized.

Neutron Imaging Beamlines at DOE User Facilities

Each beamline has unique characteristics. To determine the user facility and beamline best suited to your science questions, see additional information and beamline contacts at the links below.