Acquisition of a State-of-the-Art Thermal Ionization Mass Spectrometer

购置最先进的热电离质谱仪

• 批准号: 0549300
• 负责人: Richard Walker
• 金额: $ 26.5万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-01 至 2008-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0549300&HistoricalAwards=false
• 关键词: Acquisition; State; Art; Thermal; Ionization

EAR-0549300WalkerThe new generation of thermal ionization mass spectrometer to be purchased via funding from this grant will allow scientists at the University of Maryland to measure certain isotopic ratios to better than +5 ppm, a substantial improvement relative to measurements with our current equipment that are limited to approximately +25 ppm. The improved measurement capability will allow us to pursue a host of new Earth science projects that require ultra-high precision analysis. Specific analytical tasks to be tackled include the ultra-high precision analysis of 186Os/188Os ratios of mantle-derived rocks from putative plume sources, such as Hawaii, the Canary Islands and the Azores. Our previous work has suggested that enrichments in 186Os in some putative plume sources may reflect prior incorporation of outer core materials. We will continue to pursue this concept utilizing the superior measurement capabilities of the new instrument. We will also use the new instrument to test this hypothesis via examination of isotopes of tungsten. Cosmochemical observations coupled with mass balance arguments imply that Earth's core is depleted in 182W compared to the silicate portion of the Earth. Very slight depletions in this isotope in plume derived magmas would potentially implicate incorporation of core material. The predicted effects are so small that only the highest precision measurements, made possible with the new instrument, provide sufficient resolution necessary for this project. Unequivocal identification of a core component in a plume-derived rock could potentially settle major questions in geodynamics.***

新一代的热电离质谱仪将通过这笔赠款的资金购买，将允许科学家在马里兰州的大学测量某些同位素比优于+5 ppm，一个实质性的改进相对于测量与我们目前的设备被限制在约+25 ppm。改进后的测量能力将使我们能够开展一系列需要超高精度分析的新地球科学项目。具体的分析任务包括对来自假定的地幔柱来源（如夏威夷、加那利群岛和亚速尔群岛）的幔源岩石的186 Os/188 Os比值进行超高精度分析。我们以前的工作表明，在某些假定的羽流源中，186 Os的富集可能反映了外核物质的事先掺入。我们将继续利用新仪器的上级测量能力来实现这一概念。我们还将使用新仪器通过检查钨的同位素来验证这一假设。宇宙化学的观测加上质量平衡的论点意味着，与地球的硅酸盐部分相比，地核的182 W是耗尽的。在羽流衍生岩浆中，这种同位素的非常轻微的消耗可能涉及核心物质的掺入。预测的影响是如此之小，只有最高精度的测量，使新的仪器，提供足够的分辨率为这个项目所必需的。在地幔柱衍生岩石中明确识别核心成分可能会解决地球动力学中的主要问题。