| 英文摘要: | This award will fund the acquisition of the latest generation of a noble gas mass spectrometer for the newly established Noble Gas Laboratory at the University of California Davis. We are a world leader in isotope geochemistry, and our laboratory advances the NSF mission to nurture progress in the basic sciences and to train a new generation of scientists in analytic and technical skills. We are the only laboratory in the United States actively involved in high-precision multi-collector measurements of Ne, Ar, Kr, and Xe in samples from Earth's mantle. These measurements allow us to address fundamental questions related to when and from where Earth's water and other volatile elements were delivered, the role of giant impacts in melting the Earth and eroding the early atmosphere, and the early differentiation and degassing history of our planet. The acquisition of the new instrument will provide unrivalled analytical capabilities that enable us to remain world leaders in the development of techniques in analytic geochemistry and applications in the field of Earth's accretion, differentiation and its early history, including the formation and composition of the atmosphere. The new instrument will provide state-of-the-art analytical training for postdoctoral fellows, graduate students and undergraduate students. The research generated from the new instrument will be shared broadly through peer-reviewed journals, public lectures and by engaging with K-12 classrooms at Davis.
The proposal funds the acquisition of a new high-resolution multicollector Nu Noblesse HR noble gas mass spectrometer for research on Earth?s origin and evolution in the newly established Noble Gas Laboratory at the University of California Davis. The instrument is capable of obtaining a mass resolving power of 6000, sufficient to resolve isobaric interferences of 40Ar++ on 20Ne+, 20NeH on 21Ne, H35Cl on 36Ar and H37Cl on 38Ar. The instrument is configured with 5 detector assemblies, with each detector assembly consisting of a faraday cup and an electron multiplier. The high mass faraday will be equipped with a 10 to the power 11 ohm amplifier for measuring large beams (4He and 40Ar) while the 4 other faradays will be equipped with a 10 to the power 12 ohm amplifier. The detector assembly significantly improves upon existing multicollection capabilities, particularly for the Xe isotopes. With the acquisition of the new instrument, a broad range of research topics will be addressed using the Nu Noblesse HR including early Earth research, geochemical evolution of the mantle-atmosphere system, Earth interior-exosphere interactions and surface processes. In particular, it will allow us to keep playing a leadership role in early Earth research and will provide key new information on the acquisition of terrestrial volatiles, the formation of the atmosphere, magma ocean degassing, degassing of the Hadean Earth and the subsequent evolution of the mantle-crust-atmosphere system. The proposed acquisition of the new instrument would free up time on the existing instrument and allow us to have a dedicated new mass spectrometer for high-quality heavy noble gas work, which in turn would allow us to form more effective collaborations on a wide range of research projects with researchers at and outside of UC Davis. |