In-situ X-ray tomographic imaging under extreme conditions: a proof of concept study

极端条件下的原位 X 射线断层成像：概念验证研究

基本信息

批准号：
NE/I016333/1
负责人：
Geoffrey Bromiley
金额：
$ 5.96万
依托单位：
University of Edinburgh
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2011
资助国家：
英国
起止时间：
2011 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FI016333%2F1
关键词：
situ ray tomographic imaging under

项目摘要

Performing experiments under high pressure/temperature (P/T) conditions allows us to study how materials behave in Earth's deep interior, a key step in understanding processes which formed and constantly reform the Earth. Developing new techniques for studying earth materials under these conditions provides new insight into the workings of our planet. In X-ray microtomography (CT) a sample is rotated in an X-ray beam and transmission of radiation through the sample recorded by a detector. As with medical CAT scanning, data is then used to construct 3d models of the internal structure of solid objects, although CT can also give qualitative data on the distribution of components in complex systems. Most importantly, the technique is non-destructive and samples can be studied by CT many times to observe how they evolve with time. As such, CT is ideally suited to in-situ investigations, where changes in a sample under non-ambient conditions are observed. We will test the viability of developing a novel device to study the internal structure of materials at high P/T conditions, and also whilst they are deforming. This proof-of-concept study results from 2 recent advances: (1) development of the rotational Paris-Edinburgh cell (roPEC), a device designed to allow in-situ investigations of samples held at high P/T whilst they are deforming, and (2) development of a state-of-the-art CT instrument in the School of GeoSciences, University of Edinburgh, which was specially designed to facilitate in-situ CT studies of geologically important materials. To date, only one instrument has been developed to perform detailed CT under extreme conditions. This device was developed at the APS synchrotron in the USA. Synchrotrons are intense radiation sources which produce high energy X-rays capable of penetrating much more deeply into materials than lab-based sources, and are well suited for in-situ investigations. However, obtaining beamtime at synchrotrons is very competitive; in-situ high P/T CT investigations typically take several days for one experiment which prohibits detailed investigations, and the full potential of in-situ high P/T CT has yet to be realised. We hope to develop a new device (rotating tomography Paris-Edinburgh Cell, rotoPEC) which has the key advantage that it can used for in-situ CT using both synchrotron radiation and lower intensity lab sources. This device will be based on the roPEC, in which samples are pressurised between 2 carbide anvils, heated using an internal furnace, and deformed by rotating one of the anvils, but modified to allow full rotation of the entire sample in an X-ray beam, as required in CT. The roPEC was designed for in-situ studies, and allows X-ray beams to reach the sample with minimal, unwanted absorption. It is also small enough to be transported and installed at synchrotron sources or on other lab equipment, including the CT instrument at Edinburgh. However, before constructing a rotoPEC we need to conduct a feasibility study. Specifically we will: (1) test the potential and limitations of a rotoPEC (how much detail can we observe in samples under extreme conditions...are there limitations in the types of material we can study?). As well as testing the potential of a rotoPEC this information is also required in its future design; (2) test a new type of anvil which is X-ray transparent and would increase the volume of sample which could be 'seen' during CT -the performance of transparent anvils during deformation is critical, but remains untested; (3) further develop sample assemblies used in the roPEC to minimise unwanted absorption and increase sample resolution. Whilst conducting this work we will also study the structure of melt in 2 geologically important systems: Fe-rich melt in peridotite (did deformation help Earth to form an Fe-rich core during early stages of planet formation?) and basaltic melt in olivine (how is magma transported beneath mid-oceanic ridges?).

在高压/温度（P/T）条件下进行实验使我们能够研究材料在地球深内部的表现，这是理解形成并不断改革地球的过程的关键步骤。开发在这些条件下研究地球材料的新技术为我们的星球运作提供了新的见解。在X射线显微镜图（CT）中，样品在X射线束中旋转，并通过检测器记录的样品传播辐射。与Medical Cat扫描一样，数据随后用于构建固体对象的内部结构的3D模型，尽管CT还可以提供有关复杂系统中组件分布的定性数据。最重要的是，该技术是无损的，CT可以多次研究样品，以观察它们随时间发展的方式。因此，CT非常适合原位调查，在观察到在非镜子条件下样品的变化。我们将测试开发一种新型设备以在高P/T条件下研究材料的内部结构的生存能力，在它们变形的同时。这项概念验证研究的结果是最新进展的结果：（1）旋转巴黎 - 埃德堡细胞（ROPEC）的开发，该设备旨在允许对高P/T的样品进行现场调查，而它们正在变形，（2）开发了在Edinburgh e of Edinburgh的最重要的研究，以开发，该工具是EDINBUR GEYOLICESS of EDINELICESSSSUTILLESSSUTILLESS STERTICEL int STERTICE in ant STRECTILES，是特殊设计的，该工具是特殊的，该工具是特殊的，该工具是特殊的。材料。迄今为止，只开发了一种工具来在极端条件下执行详细的CT。该设备是在美国的APS同步器开发的。同步激素是强烈的辐射源，可产生高能量X射线，能够与基于实验室的材料更深入地渗透到材料中，并且非常适合原地研究。但是，在同步基因上获得Beamtime非常有竞争力。原位高的P/T CT研究通常需要几天进行一项禁止详细研究的实验，而原位高P/T CT的全部潜力尚未实现。我们希望开发一种新的设备（旋转层析成像巴黎 - 埃德堡细胞，rotopec），其关键优势可以使用同步加速器辐射和较低强度实验室来源用于原位CT。该设备将基于ROPEC，其中样品在2个碳化物铁砧之间加压，使用内部炉加热，并通过旋转一个铁砧而变形，但经过修改以使整个样品在X射线梁中完全旋转，根据CT的要求。 ROPEC设计用于原位研究，并允许X射线梁以最少的，不需要的吸收到达样品。它也足够小，可以在同步源或其他实验室设备（包括爱丁堡的CT仪器）上运输和安装。但是，在构建Rotopec之前，我们需要进行可行性研究。具体来说，我们将：（1）测试旋转旋转的潜力和局限性（在极端条件下我们可以在样品中观察到多少细节……我们可以研究的材料类型存在局限性？）。除了测试Rotopec的潜力外，还需要在其未来的设计中进行此信息；（2）测试一种新型X射线透明的砧座，并会增加CT期间可以“看到”样品的体积 - 变形过程中透明砧的性能至关重要，但仍未测试；（3）进一步开发ROPEC中使用的样品组件，以最大程度地减少不需要的吸收并增加样品分辨率。在进行这项工作的同时，我们还将研究2种地质重要的系统中的熔体结构：橄榄石中的富含铁的熔体（变形是否有助于地球在行星形成的早期阶段形成富含铁的核心？）和基底融化橄榄石（如何在中质山脊下方运输岩浆的岩浆？）。