Applications of neutron computed tomography in the geosciences

A research program that applies neutron computed tomography (CT) to geological problems has been developed at the McClellan Nuclear Radiation Center (UCD-MNRC) owned and operated by the University of California, Davis (UCD-MNRC). The high penetration of neutrons, their sensitivity to light elements, and their special sensitivity to hydrogen (in water or organic materials) make them an ideal tool for non-destructive examination of complex materials of geological interest. There are four research foci at UCD-MNRC related to geological material characterization: (1) quantification of textures of deformed crystalline rocks; (2) properties of multi-phase flow in porous rocks and sediments; (3) distribution of organic and inorganic carbon in silicate and carbonate rocks; and (4) CO2 sequestration through fluid-rock reaction. Examples of these research activities will be presented. A new CT infrastructure is being installed at the UCD-MNRC to meet the needs of these four research programs. Among the upgrades are the development of a “micro” CT facility and standardized CT acquisition, compatible with X-ray CT. The latter will allow direct indexing between X-ray and neutron radiograph projections and subsequent CT reconstructions.