On-site, Robust Detector System for Non-destructive Chemical Analysis at Depth

The non-destructive assessment of thick, dense materials, (i.e. concrete) for infiltration of impurities, such chlorides, can be accomplished using identical methods deployed on the Moon, Mars or other asteroids. The method relies on the moderation or capture of neutrons, which interacts with specific elements to produce specific gamma-ray and neutron signals directly related to the constituents within the surface. Radiation Monitoring Devices (RMD) has developed a compact, gamma-ray and neutron detector for these types of measurements, and we plan to deploy these instruments with a pulsed neutron generator for assessing the elemental concentrations within concrete. Specifically for chlorine, the high energy gamma rays can be readily detected, while neutron spectroscopy is used to constrain the material concentrations and depths. The nature of the measurement will probe the concrete to at least a few feet down without the need for core drilling and off-site material analysis. Using existing hardware, RMD will design, fabrication, and demonstrate a system for mapping the chloride concentrations in bridge deck material.