TL dating of synthetic CaF2:U crystals

In order to investigate further the hypothesis that the TL technique fails to date samples which have received Paleoalpha doses beyond a certain limit, TL dating has been attempted on laboratory-grown, 9-year-old CaF2 crystals containing 1 to 1600 p.p.m. by weight levels of natural U as added impurities. While the undoped crystals containing 1 p.p.m. of natural U yielded the expected TL age, the other two containing 180 and 1600 p.p.m. levels of natural U gave varying underestimated ages (less even than 1 year). The TL characteristics found in CaF2 that are dependent on U concentration and their implications in TL dating are discussed. (author)