Improvements of PKUAMS for precision C-14 analysis of the project of Xia-Shang-Zhou Chronology

To meet the requirements of the Xia-Shang-Zhou Chronology project, an upgra de of the AMS facility at Peking University has been carried out, commencin g in 1996, and a new sample preparation system with high efficiency and low memory has been set up in the Department of Archaeology. A NEC MC-SNICS io n source has been installed and the injection system has been reconstructed . Computer control of the beam line has been implemented using Group 3 Cont rolNet, and a; new data acquisition system has been developed. The alignmen t and vacuum of the beam line have also been improved. The upgraded system was commissioned in 1998. Subsequent experience has led to efficient proced ures for beam tuning and C-14/C-13 measurement. A precision of 0.5% in the C-14/C-13 ratio has been achieved. Many samples have now been measured for the Xia-Shang-Zhou Chronology project. (C) 2000 Elsevier Science B.V. All r ights reserved.