EA: Acquisition of an IRMS for sulfur isotope measurements

这笔赠款将用于购买最先进的质谱仪。该仪器将用于Dottin博士的研究计划，作为布朗大学地球，环境和行星科学系的新教员。硫是元素周期表上的第十六种元素，有四种稳定的同位素（32 S，33 S，34 S和36 S）。在各种岩石材料中测量的这些同位素的比率通常提供与岩石材料在整个地质时期如何处理相关的指纹。这也可以提供洞察不同的行星进化过程中发生的时间。拟议项目的重点是购置能够高精度测量硫同位素比率的最先进仪器。该仪器将主要用于与以下方面相关的研究：（1）了解地球深部硫的起源和演变;（2）对地球大气层的演变施加限制;（3）最终解卷积与地球大气层、表面和内部相互作用相关的复杂性。该仪器也将被用作教学工具。预计本科生、研究生和博士后将在各自的项目中使用该仪器。他们将接受仪器操作和故障排除方面的培训。该仪器还将被纳入高水平的本科生/研究生课程，这将使学生接触气体源质谱，并有机会在课堂环境中的同位素实验室工作。授予的提案包含一个同位素比质谱仪（IRMS），将用于确定各种地球水库岩石的硫同位素组成的要求。IRMS的收购将支持PI（Dottin）的研究计划，PI将于2023年7月1日开始在布朗大学担任助理教授。将与最先进的IRMS完成的分析任务将广泛涵盖研究存在于多个地球水库中的硫的四重同位素组成，以确定与地球内部，表面和大气中硫循环相关的过程，以及这些过程发生的时间尺度。具体来说，Dottin计划使用该仪器：（1）确定大洋岛玄武岩中喷发的再循环成分的性质和相对年龄;（2）对原始地幔的硫同位素组成进行详细限制;（3）使用硫同位素追踪地球大陆地壳在太古代-元古代边界的演化。该仪器将包含最先进的技术，并可配备一套独特的收集器，从而能够获得硫的次要同位素的高精度测量值。除了严格获取数据的范围外，该工具还将与植根于教育、培训和地球科学多样化的努力相联系。所要求的工具将用于支持布朗大学本科生和从HBCU和其他少数民族服务机构积极招募的暑期研究本科生进行的研究。此外，该仪器将用作教育/培训工具。研究生将接受熟练操作和维护仪器和PI（Dottin）的培训计划开发使用该仪器作为教学辅助工具的课程，让广大学生接触气体源质谱和地球化学实验室应用。该奖项反映了NSF的法定使命，并通过使用该基金会的智力价值和更广泛的影响进行评估，被认为值得支持审查标准。

This grant will support the acquisition of a state-of-the-art mass spectrometer. The instrument will be used in Dr. Dottin’s research program as a new faculty member at Brown University in the Department of Earth, Environmental, and Planetary Sciences. Sulfur, the sixteenth element on the periodic table, has 4 stable isotopes (32S, 33S, 34S and 36S). Ratios of these isotopes that are measured in a variety of rock materials often provide fingerprints associated with how the rock materials have been processed throughout geologic time. Such can also provide insights into the different planetary evolutionary processes that have occurred through time. The proposed project focuses on the acquisition of a state-of-the-art instrument capable of measuring the ratios of sulfur isotopes at high precision. The instrument will primarily be used for research associated with (1) understanding the origin and evolution of sulfur in the deep Earth, (2) placing constraints on the evolution of Earth’s atmosphere, and (3) ultimately deconvoluting the complexities related to interactions among Earth’s atmosphere, surface, and interior. The instrument also will be used as a teaching tool. It is anticipated that undergraduate students, graduate students, and postdocs will use the instrument for their respective projects. They will be trained in the operation and troubleshooting of the instrument. The instrument also will be incorporated in upper-level undergraduate/graduate courses that will allow students exposure to gas source mass spectrometry and an opportunity to work in an isotope laboratory within a class setting.The awarded proposal contains a request for an isotope ratio mass spectrometer (IRMS) that will be used to determine sulfur isotope compositions of rocks from a variety of Earth reservoirs. Acquisition of an IRMS will support the research program of PI (Dottin), who will begin an assistant professorship at Brown University July 1, 2023. The analytical tasks that will be accomplished with the state-of-the-art IRMS will broadly cover studying the quadruple isotopic composition of sulfur that exists in multiple earth reservoirs to identify the processes associated with the cycling of sulfur among the Earth’s interior, surface, and atmosphere, and the timescales on which these processes occur. Specifically, Dottin plans to use the instrument to: (1) determine the nature and relative age of recycled components erupted among Ocean Island Basalts; (2) place detailed constraints on the sulfur isotope composition of the primordial mantle; and (3) to use S isotopes to track the evolution of Earth’s continental crust across the Archean-Proterozoic boundary. The instrument will contain state-of-the-art technology and can be fit with a unique set of collectors that will allow for the acquisition of high-precision measurements of the minor isotopes of sulfur. Beyond the scope of strictly acquiring data, the instrument will be connected to efforts that are rooted in education, training, and diversification of the geosciences. The instrument requested will be used to support research performed by undergraduate students at Brown University and summer research undergraduate students actively recruited from HBCU’s and other minority-serving institutions. Additionally, the instrument will be used as an educational/training tool. Graduate students will be trained in the proficient operation and maintenance of the instrument and the PI (Dottin) plans to develop courses that use the instrument as a teaching aid to expose a wide audience of students to gas source mass spectrometry and geochemistry laboratory applications.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.