Facility Support: High-Resolution X-Ray Computed Tomography Laboratory

9816020Carlson该奖项为德克萨斯大学奥斯汀分校地质科学系的高分辨率X射线计算机层析成像实验室的运营提供部分资金支持。X射线计算机断层成像是一种对不透明固体内部进行成像的非破坏性技术。为了产生图像，X射线沿着数千种不同的路径引导通过一片样品。对沿每条路径的X射线信号衰减的测量进行数学组合，以生成切片内数十万点处的线性衰减系数的值图。由于衰减主要取决于样本密度，因此结果是切片内的密度对比度图。三维图像是由连续的切片图像叠加而成的。这项技术最初是为医学诊断而开发的，现在已被用于地球科学应用，它大幅提高了X射线源的能量和强度，并将图像的空间分辨率提高了近两个数量级。在地球科学中的应用包括成像钻芯的孔隙度以了解地下水和石油的流动，成像化石标本的内部结构，对变质岩、火成岩和沉积岩的结构进行无损研究。这项奖励将使X射线计算机断层摄影实验室成为一个多用户设施，以象征性的成本向合格的研究人员开放。

9816020Carlson This award provides partial funding support for the operation of the High-Resolution X-Ray Computed Tomography Laboratory in the Department of Geological Sciences at the University of Texas, Austin. X-ray computed tomography is a non-destructive technique for imaging the interior of opaque solids. To produce images, X-rays are directed through a slice of specimen along thousands of different paths. Measurements of the attenuation of the X-ray signal along each path are combined mathematically to generate a map of values for the linear attenuation coefficient at hundreds of thousands of points within the slice. Since attenuation is mainly dependent upon specimen density, the result is a map of density contrasts within the slice. A three-dimensional image is constructed by stacking contiguous slice images. Originally developed for medical diagnosis, the technology has been adapted for earth science applications by substantially increasing the energy and intensity of the X-ray source and increasing the spatial resolution of the images by nearly two orders of magnitude. Applications in the earth sciences include imaging the porosity of drill cores to understand the flow of groundwater and oil, imaging internal structures of fossil specimens, non-destructive studies of the textures of metamorphic, igneous, and sedimentary rocks. This award will make it possible to operate the X-ray Computed Tomography Lab as a multi-user facility open to qualified researchers at nominal cost.***