Acquisition of a New TIMS for Ocean and Earth Sciences at the University of Florida

9601872 Mueller该提案寻求资金支持佛罗里达大学地质系购买和操作最先进的热电离质谱仪（TIMS）的50%成本。 拟议的文书将在三个领域提供更好的业绩： 1)该仪器将能够提供扩展的动态范围（10） 通过利用法拉第和电子测量样品离子束的能力 倍增器或闪烁型探测器。 这种能力对于利用其中单个同位素的丰度， 包括示踪剂，超过了单独的法拉第检测器的动态范围。 2)该仪器将能够提供高丰度的灵敏度在高 马萨诸塞州 相对于传统的TIMS配置， 在U-Th系列的精确测量所必需的，并提供了好处， 低质量系统，如Ca。 在使用延迟电位透镜方面的最新发展可以提供这种能力而不需要（和成本）大的， 双聚焦配置; 3)该仪器将能够高精度地测量同位素比率， 静态模式。 在这种模式下的测量是必要的，以便将增加的动态范围和扩展的丰度灵敏度的优点联合收割机结合起来， 为小样本提供最高精度，例如，那些只含有皮克 (10 g）Pb的量，以及具有低电离效率的那些，例如，日 具体的应用将受益于包括最近的地质年代学的U系列同位素分析;地质年代学和岩石成因研究的单个锆石晶体或晶体部分的分析; 用于示踪剂、年代地层学和古环境应用的非常小的样品;以及用于古古环境研究的通过同位素稀释的Sr/Ca同位素。 他们目前的质谱仪被研究生大量使用。 这些学生中约有一半是妇女，在地球科学中占少数。 佛罗里达大学为这个项目提供了360,730美元的支持， 占成本的50%。 ***

9601872 Mueller This proposal seeks funding to support 50% of the cost of acquiring and operating a state-of-the-art thermal ionization mass spectrometer (TIMS) for the Geology Department of the University of Florida. The proposed instrument will provide enhanced performance in three areas: 1) The instrument will be capable of providing extended dynamic range (10 ) through the ability to measure sample ion beans with both Faraday and electron multiplier- or scintillation - type detectors simultaneously. This capability is essential for utilizing systems in which the abundance of individual isotopes, including tracers, exceeds the dynamic range of Faraday detectors alone. 2) The instrument will be capable of providing high abundance sensitivity at high mass. This extended capability, relative to traditional TIMS configurations, is also necessary for accurate measurements in the U-Th series and provides benefits in lower mass systems such as Ca. Recent developments in the use of retarding potential lens can provide this capability without the need (and cost) of large, double focusing configurations; 3) The instrument will be capable of high precision isotopic ratio measurements in static mode. Measurement in this mode is necessary in order to combine the advantages of increased dynamic range and extended abundance sensitivity to provide maximum accuracy for small samples, e.g., those containing only picogram (10 g) quantities of Pb, and those with low ionization efficiencies, e.g., Th. Specific applications that will benefit include the analysis of U-series isotopes for recent geochronology; the analysis of individual zircon crystals or parts of crystals for geochronologic and petrogenetic studies; Pb, Sr, and Nd isotopic studies of very small samples for tracer, chronostratigraphic, and paleo-environmental applications; and Sr/Ca isotopes via isotope dilution for paleoenvironme ntal studies. Their current mass spectrometer is heavily utilized by graduate students. Approximately half of these students are women, a minority in the geosciences. The University of Florida is supporting this project with $360,730, which represents a 50% cost share. ***