Methods routinely used by Oak Ridge National Laboratory health physicists to do radiation measurements are helping University of Tennessee researchers determine the age of anthropological finds. A Dosimetry Applications Research Calibration Laboratory team is using radiation testing equipment to date finds such as a bovid (horse or cow) tooth found near an ancient human tooth on the island of Java, Indonesia. By testing the bovid tooth, researchers can determine the age of the rare human tooth while still preserving it. They conservatively estimate the tooth is 500,000 years old. The ORNL team dates sample components such as quartz, feldspar or tooth enamel by doing radiation damage dating. First, scientists determine the dose of the sample by measuring electrons that have been promoted by natural radiation in the surrounding soil into "traps" in the tooth. Next, the dose rate of the contextual material is determined using a gamma spectrometer. By dividing the dose by the dose rate, researchers can determine the relative age of the fossil. Radiation damage dating enables researchers to solve some the greatest mysteries about the history of humankind.
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