Inner shell excitation spectroscopy and microscopy

我的团队开发并使用电子冲击和基于x射线的内壳激发光谱仪器和技术进行材料分析。麦克马斯特的气相电子影响研究与加拿大光源（CLS，萨斯卡顿）和先进光源（ALS，伯克利）的光谱和显微镜光束线同步辐射材料分析相结合。我们的强项是通过对纯气体和固体材料的基础实验和计算研究，将基本的光谱理解与使用新型仪器和方法（特别是软x射线显微镜）的材料分析应用联系起来。该计划的一个主要组成部分是新仪器和新技术的发展。在未来的5年里，我们将：(1)扩大x射线光谱显微镜的仪器和应用，特别关注利用CLS光谱显微镜光束线的独特功能的领域。这些包括聚合物和纳米纤维的定位，生物学中的磁性，以及宽能量范围，多元素研究。ALS的工作也将继续，重点是帮助开发下一代扫描透射x射线显微镜，具有低于10纳米的空间分辨率和冷冻生物和环境样品的3d化学成像。麦克马斯特的其他先进显微镜——超分辨率电子显微镜（TEM， SEM），拉曼和原子力显微镜——也被使用。(2)进行气相偶极子和非偶极子电子散射的研究，并继续准弹性电子散射的激励程序。这个区域使用的是独特的自制仪器。偶极子研究为我们的x射线显微镜分析工作提供了光谱学基础，而非偶极子仪器使我们能够探测到电子散射相互作用的细节和分子电子结构的各个方面，这些方面很难用光学方法研究。电子能谱仪是学生在仪器和科学方面训练的优秀实验室工具。

My group develops and uses electron impact and X-ray based inner-shell excitation spectroscopic instrumentation and techniques for materials analysis. Gas phase electron impact studies at McMaster are combined with synchrotron radiation based materials analysis at spectroscopy and microscopy beamlines at the Canadian Light Source (CLS, Saskatoon) and the Advanced Light Source (ALS, Berkeley). Our forte is linking basic spectroscopic understanding, developed by fundamental experimental and computational studies of pure gaseous and solid materials, to materials analysis applications using novel instrumentation and methods, particularly soft X-ray microscopies. A major component of this program is the development of new instrumentation and new techniques. In the next 5 years we will: (1) expand the instrumentation and applications of X-ray spectromicroscopy, focusing in particular on areas exploiting the unique capabilities of the CLS spectromicroscopy beamline. These include mapping orientation of polymer and nanofibres, magnetism in biology, and wide energy range, multi-element studies. Work will also continue at the ALS, focusing on helping develop a next generation scanning transmission X-ray microscope, with sub-10 nm spatial resolution and 3d chemical imaging of frozen biological and environmental samples. Other advanced microscopies at McMaster - ultra-resolution electron microscopies (TEM, SEM), Raman and atomic force microscopy - are used also. (2) perform gas phase dipole and non-dipole electron scattering studies, as well as continue the exciting program in quasi-elastic electron scattering. This area uses home-built instrumentation that is unique. The dipole studies provide the spectroscopic foundation for our X-ray microscopy analytical work while the non-dipole instrument allows us to probe fine details of electron scattering interactions and aspects of the electronic structure of molecules that cannot be easily studied using optical methods. The electron spectrometers are excellent lab-based tools for student training in instrumentation and science.