Refurbishment of a VG Sector Mass Spectrometer to Gain Negative Ion Capability

来自该合同的资金将用于将密歇根大学旧的VG部门传统热电离质谱仪转换为负离子热电离质谱仪（N-TIMS）。一旦修改，该仪器将用于地质和环境研究，这些研究需要测量电负性形式的锇和硼的同位素比率。我们期待与内部和外部同事的合作，这将使工厂非常繁忙。要转换的质谱仪有“Multi-1”收集器块，有6个旧设计，短寿命，手动移动的法拉第杯。由于它们的年龄和吞吐量较长，法拉第探测器遭受了一些损坏，导致增益和峰形退化。这种磨损的最终结果是Sr和Nd同位素比值测量的精度和可重复性差。然而，由于锇和硼的同位素比例在自然界中有很大的变化，它们的测量不需要Sr和Nd同位素所需的高精度。因此，翻新仪器的电子元件并将其转换为负离子能力-但不更换收集器-将延长机器的使用寿命，并为我们提供在地质和环境科学的新领域进行研究的机会。这种N-TIMS转换将为我们各自的研究小组打开使用o和B等电负性离子的新研究领域，并为我们的学生和博士后研究人员提供一个“新工具”，以解决他们在高温地球化学、岩石学、环境地球化学、经济地质学和古海洋学方面的研究项目。同样重要的是，翻新后的仪器将用于教授学生一些基本技能，如质谱，研究问题的制定，客观数据处理和分析，以及书面和口头报告的呈现。这些技能可以应用到后来在学术界、政府或工业的工作环境中。

EAR-0345135MukasaFunds from this award are to be used to convert an old VG Sector conventional thermal ionization mass spectrometer at the University of Michigan into a negative ion thermal ionization mass spectrometer (N-TIMS). Once modified, the instrument will be used in geological and environmental studies that require the measurement of isotopic ratios for osmium and boron in their electronegative form. We anticipate collaborations with both internal and external colleagues, which will keep the facility very busy. The mass spectrometer to be converted has the "Multi-1" collector block with six old-design, short-life, Faraday cups that are moved manually. Because of their advanced age and throughput, the Faraday detectors have suffered some damage leading to degradation in gain and peak shape. The net result of this wear and tear is poor precision and reproducibility in the measurements of Sr and Nd isotopic ratios. However, because osmium and boron isotopic ratios have very large variations in nature, their measurements do not require the high precision necessary for Sr and Nd isotopes. Therefore, refurbishing the electronic components of the instrument along with converting it to negative ion capability - but not replacing the collectors - will extend the machine's life and afford us the opportunity to do research in new areas of the geological and environmental sciences. This N-TIMS conversion will open our respective groups to new areas of research that use electronegative ions, such as Os and B, and provide our students and postdoctoral research fellows with a "new tool" for tackling their research projects in high-temperature geochemistry, petrology, environmental geochemistry economic geology, and paleooceanography. Just as importantly, the refurbished instrument will be used to teach students some fundamental skills such as mass spectrometry, formulation of research problems, objective data processing and analysis, and the presentation of written and oral reports. These skills can be applied to later work situations in academia, government, or industry.