Grant: Research Tools and Instruments - Category 1 (<$150,000)

Radiocarbon, C-14, is a naturally ubiquitous isotope that has many uses.  It is most known for its use as a dating technique.  It is also widely used as a tracer in biomedical experiments where the C-14 is substituted for non-radioactive C-12.  We wish to explore two other uses of C-14 using the proposed equipment.   When cosmic rays interact with exposed atoms in rock and soil, one of the many isotopes produced is C-14.  Only 15 atoms of C-14 are produced per year in a 1 g quartz crystal, exposed for instance, on a beach in the Arctic.  If we can build a vacuum system that allows negligible contamination (no lab air, no C from fixtures of the system) it is possible to count the low concentration of C-14 in 5 to 7 g of quartz that has been exposed for thousands of years.  The concentration provides information about the exposure age and erosion history of the rock, with which we can answer important questions regarding , for instance, the frequency of storms and earthquakes, the history of climate changes, and timing of human occupancy.   Our second use of extremely low abundances of C-14 is in the study of specific organic molecules and their application to environmental science and paleoceanography.  For instance, by measuring the C-14 abundance in fatty acids of microbes, it is possible to determine if the microbes are biograding specific pollutants and petroleum contaminants in various aquatic and terrestrial environments (there is no C-14 in petroleum due to radioactive decay).  However, the extraction of such small masses (tens of micrograms of C-14) requires a low-background vacuum line that does not yet exist in Canada and is not readily accessible at the few possible facilities worldwide.  In addition to two technicians, students and visitors will receive training in vacuum systems, isotope and environmental geochemistry, and geochronology.  The system will be unique to Canada and will help these researchers and their teams to assume leadership in designing innovative C-14 experiments.