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

9816020卡尔森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射线计算机断层扫描实验室的运作提供部分资金支持。X射线计算机断层摄影术是一种用于对不透明固体内部成像的非破坏性技术。为了产生图像，X射线沿着沿着数千条不同的路径穿过一片标本。沿沿着每条路径的X射线信号的衰减的测量被数学地组合以生成在切片内的数十万个点处的线性衰减系数的值的图。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图。通过堆叠连续切片图像来构建三维图像。该技术最初是为医疗诊断而开发的，现已通过大幅增加X射线源的能量和强度并将图像的空间分辨率提高近两个数量级而适用于地球科学应用。在地球科学中的应用包括成像岩心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，火成岩和沉积岩的纹理进行非破坏性研究。该合同将使X射线计算机断层扫描实验室成为一个多用户设施，以名义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.***