Conveners
New Isotopes Methodologies
- Kimikazu Sasa (University of Tsukuba)
New Isotopes Methodologies
- Stefan Pavetich (The Australian National University)
Description
Developments in ion injection and instrumentation interfacing for AMS. Topics include ion production, gas source AMS, and gas chromatography interfacing.
The mass region between 90 and 100 amu is home to several long-lived radionuclides that are interesting for various applications of AMS. Two examples are $^{93}$Zr, and $^{99}$Tc with half-lives of ~1.6 Ma, and ~211 ka respectively. Both isotopes are high-yield fission products and were produced and distributed in the environment by atmospheric nuclear weapons tests and nowadays are produced...
Concentrations of the anthropogenic radionuclide $^{99}$Tc (t$_{1/2}$ = 2.1$\times$ 10$^5$ yrs) have been extensively studied in the Irish Sea, where the Sellafield reprocessing plant is responsible for high concentrations of 2$\times$ 10$^9$ atoms/ml. However, a comprehensive understanding of its global distribution and physico-chemical behavior in the environment remains limited. The...
The 10Be/7Be ratio is a sensitive tracer for the study of atmospheric transport, particularly with regard to stratosphere-troposphere exchange. Measurements with high accuracy and efficiency are crucial to 7Be and 10Be tracer studies. Full stripping method of 7Be have been carried out by few larger AMS. However, for low energy AMS that is difficult to obtain efficient full stripping Be, the...
The long-lived noble-gas isotope 81Kr is the ideal tracer for old water and ice with ages of 0.1 – 1 million years, a range beyond the reach of 14C. 81Kr-dating, a concept pursued over the past six decades, is now available to the earth science community at large. This is made possible by the development of the Atom Trap Trace Analysis (ATTA) method, in which individual atoms of the desired...
Here we search the 28Si doubly charged negative ion (28Si DCNI) with Accelerator Mass Spectrometry (AMS). Five kinds of silicon including samples made of Si, Si+Fe, Si3N4, SiO2+Fe, and Si3N4+Fe were prepared to find 28Si DCNI. These samples were loaded into an AMS, which was a tandem type machine with a negative ion source by cesium sputtering (SNICS). The ions produced from these samples went...
Atom Trap Trace Analysis (ATTA) is a technique that utilizes laser to selective capture and detect individual atoms of the desired isotope. This technique loads atoms into a magneto-optical trap (MOT) through laser cooling and trapping, realizing high sensitivity and detection efficiency of the desired isotope.
Due to the use of multi-photon repetitive excitation in the experiment, the...
Cosmogenic Ar-39 dating is an emerging technique in tracing groundwater flow, dating mountain glacier ice, and mapping ocean circulation. With a half-life of 268 years, its dating range covers from 50 to 1800 years. Atom Trap Trace Analysis (ATTA) is a laser-based method that trapping and detecting individual neutral isotope atoms in a magneto-optical trap, with high selectivity and...
