Xiangdong Ruan

99Tc measurements with accelerator mass spectrometry at CIAE

Abstract 236 U is a long-lived radioactive isotope which is produced principally by thermal neutron capture on 235 U. 236 U may be potentially applied in geological research and nuclear safeguards. Accelerator mass spectrometry is presently the most sensitive technique for the measurement of 236 U and a measurement method for long-lived heavy ion 236 U has been developed. The set-up uses a dedicated injector and the newly proposed 208 Pb 16 O 2 - molecular ions for the simulation of 236 U ion transport. A sensitivity of lower than 10 −10 has been achieved for the isotopic ratio 236 U/ 238 U in present work.

AMS Radiocarbon Dating of an Ancient Pottery Workshop in Hepu County, China

An ancient pottery workshop belonging to the Han Dynasty was excavated in Caoxie village, Hepu County. Caoxie village is an important archaeological site in Hepu County, Beihai City, in south Chinas Guangxi Zhuang Autonomous Region. It is believed that Hepu County was the oldest departure point on the ancient maritime trading route during the Han Dynasty (206 BC to AD 220) due to the ideal natural geographical conditions and the existence of a large number of Han tombs. Radiocarbon measurements on wood and charcoal samples from the Caoxie village site were performed at the Peking University AMS facility (PKU-AMS), Beijing, and the Centre for Isotopic Research for Cultural and Environmental Heritage (CIRCE) at Naples Second University, Italy. Calibrated ages were obtained with code CALIB 5 (Stuiver and Reimer 1993). The results of these measurements are presented and the related chronology is discussed.

The AMS Measurements and Its Applications in Nuclear Physics at China Institute of Atomic Energy (CIAE)

Accelerator Mass Spectrometry (AMS), initiated in late 1970s at McMaster university based on the accelerator and detector technique, has long been applied in the studies on archaeology, geology, and cosmology, as a powerful tool for isotope dating. The advantages of AMS in the analysis of rare nuclides by direct counting of the atoms, small sample size and relatively free from the interferences of molecular ions have been well documented. This paper emphasizes that AMS can not only be used for archaeology, geology, environment, biology and so on, but also served as a unique tool for nuclear physics research. In this paper, the determination of the half‐lives of 79Se, the measurements of the cross‐sections of 93Nb(n,2n)92gNb and 238U(n,3n)236U reactions, the detection and determination of ultratrace impurities in neutrino detector materials, and the measurement of the fission product nuclide 126Sn, are to be introduced, as some of examples of AMS applications in nuclear research conducted in AMS lab of Chi...