• Testing the Limits: Radiocarbon Dating and the End of the Late Bronze Age

      Hagens, Graham (Department of Geosciences, The University of Arizona, 2006-01-01)
      Archaeometry is becoming an increasingly important tool in chronological research related to events in the Ancient Near East during the 2nd millennium BCE. This paper is a review of recently published radiometric results in an attempt to establish the probable dating range for one particular event that occurred during the last quarter of that millennium, the end of the Late Bronze Age. The conclusion is that in spite of significant improvements in methodology in recent years, the quantity and quality of radiocarbon data are still insufficient to define the range of that date to much better than a century. It is concluded that the most likely date of the Late Bronze/Iron Age transition (here defined by the arrival of Mycenaean LH IIIC:1b pottery in the Levant) is somewhere in the 8-decade range between ~1170 to 1100 BCE. A comparative study of archaeological and historical evidence would appear to favor the lower value.
    • The 3MV Multi-Element AMS in Xi'an, China: Unique Features and Preliminary Tests

      Zhou, Weijian; Zhao, Xiaolei; Xuefeng, Lu; Lin, Liu; Zhengkun, Wu; Peng, Cheng; Wengnian, Zhao; Chunhai, Huang (Department of Geosciences, The University of Arizona, 2006-01-01)
      A 3MV multi-element accelerator mass spectrometer (AMS) has been installed in Xian, China, and preliminary tests have been completed. The results of both background and precision tests for 4 nuclides are 3.1 x 10^-16, 0.2% (14C); 1.8 x 10^-14, 1.4% (10Be); 2.3 x 10^-15, 1.14% (26Al); and 2.0 x 10^-14, 1.75% (129I). The unique features of this facility are the newly developed ion source accepting solid and CO2 samples; the specially designed low-energy injector, including a beam blanking unit and Q-snout; the acceleration tube structure with the combined magnetic and electrostatic suppression; and the function of the slit stabilization in the post-acceleration system. These features are discussed in terms of the end-users point of view.