Collaborative Research: Damage Defects and Diffusion of Noble Gases in Minerals: He in Zircon as a Model System

合作研究：矿物中稀有气体的损伤缺陷和扩散：锆石中的 He 作为模型系统

基本信息

批准号：
1427468
负责人：
Kenneth Farley
金额：
$ 7.63万
依托单位：
California Institute of Technology
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2014
资助国家：
美国
起止时间：
2014-09-01 至 2016-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1427468&HistoricalAwards=false
关键词：
Collaborative Research Damage Defects Diffusion

项目摘要

The noble gases (helium, neon, argon, krypton, xenon, and radon) play a central role in understanding a wide variety of Earth and planetary processes, from tracing the origins of meteorites, to the differentiation of Earth's mantle, to dating the timing and rates of geologic processes. However, while we can now measure noble gases in minerals very precisely, our understanding of how they are incorporated into, migrate through, and are lost from minerals is simplistic and likely wrong in important ways. This work will use a series of novel experiments to understand the behavior of one noble gas, helium, in one mineral, zircon, to build a general understanding of noble gas behavior in other systems.The ability to measure distinct isotopes of helium in zircon specimens with differing amounts and types of crystal defects and crystallographic orientations (as well as the widespread utility of the radiogenic He radioisotopic dating system) make this an ideal model system for this work. The project will focus on radiogenic 4He, as well as 3He and 4He implanted or generated in situ in zircons with varying amounts of radiation damage from both heavy nuclide recoil and light ion or neutron damage, and will also examine the effects of damage defect annealing on He behavior. These experiments will distinguish between the effects of damage defects as traps, tortuosity enhancers, and fast-paths at various levels of pro- and retrograde accumulation.

高贵气体（氦气，霓虹灯，氩，k，氙气和ra）在理解各种地球和行星过程中起着核心作用和地质过程的速度。但是，尽管我们现在可以非常精确地测量矿物质中的贵重气体，但我们对它们如何纳入，迁移并从矿物质中丢失的理解在重要方面是简单的，可能是错误的。这项工作将使用一系列新颖的实验来了解一种贵重气体，氦气，一种矿物锆石的行为，以在其他系统中对贵重气体行为建立一般的理解。晶体缺陷和晶体学方向的不同量和类型（以及放射性HE放射异位测年系统的广泛效用）使此工作成为这项工作的理想模型系统。该项目将着重于放射性4HE，以及3HE和4HE植入或在原位植入或产生的锆石，而重型核素后坐力和轻离子或中子损害的辐射损伤量变化，还将检查损害缺陷的效果他的行为。这些实验将区分损伤缺陷作为陷阱，曲折度增强子和各种趋势累积和逆行积累的快速路径的影响。