With significant advances in mass spectrometry for isotope analysis in the last decade,e.g.,negative thermal ionization mass spectrometry and multi-collector inductively coupled plasma mass spectrometry,high-precision...With significant advances in mass spectrometry for isotope analysis in the last decade,e.g.,negative thermal ionization mass spectrometry and multi-collector inductively coupled plasma mass spectrometry,high-precision(ppm-level)measurements of tungsten(W)isotopes have been widely used for early earth differentiation processes,such as metal-silicate segregation,melting and crystallization processes during the magma ocean,and putative core-mantle exchange and dynamics.Here,we give a brief review of works on ^(182)W anomalies in terrestrial samples,including methods,results,explanations,implications,and prospects.The review will be presented by including the following parts:the introduction of W isotopes and the short-lived radioactive ^(182)Hf-^(182)W system;data notations and W isotope measurement methods;^(182)W anomalies observed in terrestrial samples;a summary of models developed for interpreting origins of positive and negative ^(182)W anomalies;future prospects.展开更多
In order to improve the accuracy of accelerator mass spectrometry （AMS） measurement for 182Hf/180Hf, a series of measurements have been taken in the AMS laboratory at the China Institute of Atomic Energy （CIAE）. T...In order to improve the accuracy of accelerator mass spectrometry （AMS） measurement for 182Hf/180Hf, a series of measurements have been taken in the AMS laboratory at the China Institute of Atomic Energy （CIAE）. The major ones include the instantaneous monitoring of 180HfF5- current, testing the stability of transmission, the alternate measurements of an unknown sample and standard, and the origin identification and minimization of background 182W. The experimental details and the improvement in the measurement accuracy, as well as some useful suggestions for better satisfying the requirements of certain practical applications, are presented in this paper.展开更多
A good 182Ta Mossbauer source and an apparatus designed specially were made. 182W transmission Mossbauer experiments were successfully carried out, both of the source and absorber at liquid nitrogen temperature. It wa...A good 182Ta Mossbauer source and an apparatus designed specially were made. 182W transmission Mossbauer experiments were successfully carried out, both of the source and absorber at liquid nitrogen temperature. It was found that reducing background radiation is very important to observe clear resonant effect.展开更多
基金supported by the Strategic Priority Research Program(B)of CAS(XDB41000000)Pre-research Project on Civil Aerospace Technologies No.D020202 is funded by the Chinese National Space Administration(CNSA)and Chinese NSF projects(42130114)。
文摘With significant advances in mass spectrometry for isotope analysis in the last decade,e.g.,negative thermal ionization mass spectrometry and multi-collector inductively coupled plasma mass spectrometry,high-precision(ppm-level)measurements of tungsten(W)isotopes have been widely used for early earth differentiation processes,such as metal-silicate segregation,melting and crystallization processes during the magma ocean,and putative core-mantle exchange and dynamics.Here,we give a brief review of works on ^(182)W anomalies in terrestrial samples,including methods,results,explanations,implications,and prospects.The review will be presented by including the following parts:the introduction of W isotopes and the short-lived radioactive ^(182)Hf-^(182)W system;data notations and W isotope measurement methods;^(182)W anomalies observed in terrestrial samples;a summary of models developed for interpreting origins of positive and negative ^(182)W anomalies;future prospects.
基金Supported by National Natural Science Foundation of China(10705054)
文摘In order to improve the accuracy of accelerator mass spectrometry （AMS） measurement for 182Hf/180Hf, a series of measurements have been taken in the AMS laboratory at the China Institute of Atomic Energy （CIAE）. The major ones include the instantaneous monitoring of 180HfF5- current, testing the stability of transmission, the alternate measurements of an unknown sample and standard, and the origin identification and minimization of background 182W. The experimental details and the improvement in the measurement accuracy, as well as some useful suggestions for better satisfying the requirements of certain practical applications, are presented in this paper.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 19675017).
文摘A good 182Ta Mossbauer source and an apparatus designed specially were made. 182W transmission Mossbauer experiments were successfully carried out, both of the source and absorber at liquid nitrogen temperature. It was found that reducing background radiation is very important to observe clear resonant effect.
