Optical Radiopurity Material Measurements (35c)

This Small Business Innovation Research proposal seeks to develop a laser-based diagnostic to quantify radioactive impurities present in clean materials at radiation levels < 1 µBq/kg. The proposed diagnostic will address the need for an analytical instrument to screen clean/radiopure for U, Th, and K incorporated into rare-event nuclear physics experiments. Existing radioassays suffer from long measurement times or matrix interference effects that limit achievable detection limits or complicate the analysis on a material-by-material basis. The overall objective of the program is to develop a laser-based magneto-optical atomic polarization spectroscopy technique that is capable of quantifying 238U, 232Th, and K in clean materials – the dominant primordial isotopes contributing to a radiation background in underground rare-event nuclear physics experiments. The primary objective of the Phase I program is to execute proof-of-concept experiments demonstrating that the proposed laser-diagnostic is sufficiently sensitive to meet the required limits of detection for these radiocontaminants. In the Phase I program a testbed will be assembled to execute proof- of-concept experiments demonstrating the sensitivity of the proposed laser-based diagnostic for 238U quantification. These experiments will provide the information required to optimize the design of a Phase II prototype instrument. A market assessment will be conducted for the technology targeting the areas of nuclear safeguards and nuclear forensics. The potential water quality monitoring market for metals of concern to public health will also be evaluated. The proposed technology can be broadly applied to monitoring soil and water for metals contamination. The technology is particularly relevant for water monitoring applications of metals such as mercury, lead, arsenic, cadmium, and manganese that represent a risk to public health. The technology will have sufficient limits of detection to monitor the aforementioned elements below the maximum permissible exposure limits in real time field measurements.