MRI-R2: Development of a High-Flux Deuteron-Deuteron Fusion Neutron Source for 40Ar/39Ar Geochronology

MRI-R2：开发用于 40Ar/39Ar 地质年代学的高通量氘核-氘核聚变中子源

• 批准号: 0960138
• 负责人: Paul Renne
• 金额: $ 78.22万
• 依托单位: Berkeley Geochronology Center
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0960138&HistoricalAwards=false
• 关键词: MRI; R2; Development; Flux; Deuteron

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This project will develop a facility to use nuclear fusion of deuterium atoms and ions to create a large concentration of neutrons with uniform energy of 2.45 million electron volts. The fusion reaction has been successfully induced in previous experiments, but this project will use a novel radially inward-focussing deuterium ion beam geometry to pursue a neutron concentration 1000 or more times higher than previously achieved. This neutron generator will be used to irradiate geological samples for the argon-40/argon-39 dating method, in which potassium-39 must be converted to argon-39 through neutron capture. The source of neutrons for this widely used dating method has previously been conventional nuclear reactors powered by fission of uranium, producing a broad range of neutron energies with several suboptimal effects. In contrast, the device to be developed by this project will reduce atomic recoil and unwanted nuclear reactions, thus producing more accurate age information with less radiological risk to analysts, and without generating hazardous radioactive waste. These improvements will enhance the ability to accurately date fine-grained minerals such as clays, whose ages are often useful as a guide for petroleum and ore deposit exploration. Other likely applications include the chronology of human evolution and of the early solar system. The device will be useful for applications beyond dating, specifically including trace element geochemistry, nuclear medicine, materials science, and condensed matter physics. The ability to provide rapid neutron activation data will be applicable to the design of a next generation of fission reactors for nuclear power. The project will provide training to students and postdoctoral researchers and thus contribute to replenishing the depleted pipeline of early career scientists with expertise in nuclear sciences, thereby addressing growing concerns arising from national security and energy needs. The project will also enhance cross-disciplinary collaboration between nuclear scientists and earth scientists.

该奖项是根据2009年《美国复苏与再投资法》（公法111-5）资助的。 该项目将开发一种利用氘原子和离子的核融合的设施，以创建大量的中子，其均匀能量为245万台电子伏特。 在先前的实验中已成功诱导了融合反应，但是该项目将使用一种新型的径向向内的氘离子束几何形状来追求比以前所获得的中子浓度高1000倍或更多。 该中子发电机将用于用于氩40/Argon-39约会方法的地质样品，其中必须通过中子捕获将钾39转换为氩39。这种广泛使用的约会方法的中子的来源先前是传统的核反应堆，该反应堆是由铀裂变提供动力的，产生了多种次优影响的广泛的中子能量。相比之下，该项目要开发的设备将减少原子后坐力和不必要的核反应，从而产生更准确的年龄信息，而放射线分析师的放射学风险较小，而不会产生危险的放射性废物。这些改进将增强准确约会细粒矿物质（例如粘土）的能力，粘土通常可以作为石油和矿石沉积探索的指南有用。其他可能的应用包括人类进化和早期太阳系的年代。该设备将对超出约会的应用程序有用，特别是包括痕量元素地球化学，核医学，材料科学和冷凝物理物理学。提供快速中子激活数据的能力将适用于下一代核电裂变反应器的设计。该项目将为学生和博士后研究人员提供培训，从而为早期职业科学家的耗尽管道提供核科学专业知识，从而解决了由于国家安全和能源需求而引起的越来越多的担忧。该项目还将增强核科学家与地球科学家之间的跨学科合作。