IMPROVEMENTS AND APPLICATIONS OF AMS RADIOCARBON MEASUREMENT AT PEKING-UNIVERSITY

AMS radiocarbon measurements were started at Peking University in 1992 with a modified HICONEX 834 ion source. Some archaeological samples w ere measured at a sensitivity of 10(-14) with ca. 1.7% precision for m odern samples. We have made many improvements in our first two years o f operation: a high-intensity Cs sputtering ion source was installed; the graphite sample preparation technique was investigated; and the sy stem stability has been improved. The blank sample background is curre ntly ca. 0.006 MC and a precision within 1% can be reached for modern samples. Geological, archaeological, environmental and biomedical samp les can be measured routinely. We present some typical applications.