EGU21-1959
https://doi.org/10.5194/egusphere-egu21-1959
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Analyzing Ca-41 sample at 1E-15 abundance level with cold atom trap techniques

Tian Xia, Tong-Yan Xia, Wei-Wei Sun, Wei Jiang, and Zheng-Tian Lu
Tian Xia et al.
  • University of Science and Technology of China, Hefei National Lab, Hefei, China (txia1@ustc.edu.cn)

On earth, Calcium-41 is produced as a cosmogenic isotope via neutron capture process, leaving a natural isotopic abundance of 10-15 on earth surface. Calcium is also of vital importance for the metabolism of biological organisms. Consequently, analysis of the long lived radioactive isotope Calcium-41 is of great importance in geoscience, archeology and life sciences. The half-life of Calcium-41 is 1.03 x 105 years. It is a good candidate in dating rock and bone samples ranging from 50,000 to 1,000,000 years old.

The available techniques for trace analysis of Calcium-41 include accelerator mass spectrometry (AMS) and resonance ionization mass spectroscopy (RIMS). The detection limit of RIMS is on the level of 10-11 due to the interference of Potassium-41, which is difficult to remove from the sample. The analysis with high-energy AMS is more expensive than the table top apparatus, and it also faces similar problem as RIMS method.

We develop an atom trap trace analysis(ATTA) apparatus for Calcium-41 analysis to the sensitivity of 10-15 abundance level by one hour of single atom counting. ATTA uses laser tuned at the resonant wavelength for a specific element and isotope to slow down and capture single atom by fluorescence radiation. It has a very high selectivity of element and isotope, which is more advantageous than AMS and RIMS to avoid isobar interference. ATTA has been used in analysis of Krypton-81, Argon-39 dating of the hydrological samples. This work on high sensitivity Calcium-41 analysis is very promising in dating the geochemical sample to determine the exposure ages of rocks or in cosmochemistry for investigations on terrestrial ages.

How to cite: Xia, T., Xia, T.-Y., Sun, W.-W., Jiang, W., and Lu, Z.-T.: Analyzing Ca-41 sample at 1E-15 abundance level with cold atom trap techniques, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1959, https://doi.org/10.5194/egusphere-egu21-1959, 2021.

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