SPP 1134: Transient structures in condensed matter investigated by ultrafast x-ray techniques

SPP 1134：通过超快 X 射线技术研究凝聚态物质中的瞬态结构

• 批准号: 5471573
• 金额: --
• 依托单位: Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie (MBI)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2002
• 资助国家: 德国
• 起止时间: 2001-12-31 至 2007-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5471573?language=en
• 关键词: SPP; 1134; Transient; structures; condensed

The priority programme is devoted to ultrafast structural changes in condensed matter which are studied by ultrafast x-ray techniques. The generation and characterization of ultrashort hard x-ray pulses are being combined with detecting and analyzing processes of structural change by x-ray diffraction and absorption. This research aims at a basic understanding of the relevant nonequilibrium processes occurring on a time scale between 10 fs and 10 ps and the underlying microsopic mechanisms. In this way, relationships between structure and function of the systems investigated will be elucidated.Photoinduced ultrafast phase transitions, e.g., from the solid to the liquid phase and/or between different crystalline structures, as well as the dynamics of crystal lattices, e.g., the propagation of phonon wave packets or shock waves, are studied in metals, semiconductors, and semiconductor nanostructures. Reversible or irreversible changes of atomic position are directly monitored by time-resolved x-ray diffraction. Such experiments are combined with theoretical simulations of the microscopic structural changes. In crystallized macromolecules, i.e. biopolymers, chromopeptides and proteins, elementary steps of (bio)chemical reactions are studied, in disordered systems, e.g., the liquid phase, transient structures under the influence of the environment. Research on laser based compact sources for ultrashort x-ray pulses and new concepts for x-ray targets and optical components represents an important aspect of this work which is worked on in close collaboration of the groups participating in the priority programme.

优先方案致力于利用超快X射线技术研究凝聚态物质的超快结构变化。超短硬X射线脉冲的产生和表征与X射线衍射和吸收探测和分析结构变化的过程相结合。这项研究的目的是对在10ps到10ps之间的时间尺度上发生的相关非平衡过程和潜在的微视机制有一个基本的了解。在金属、半导体和半导体纳米结构中，研究了光致超快相变，例如从固相到液相和/或不同晶体结构之间的光致超快相变，以及晶格的动力学，例如声子波包或冲击波的传播。用时间分辨X射线衍射法直接监测原子位置的可逆或不可逆变化。这些实验与微观结构变化的理论模拟相结合。在结晶的大分子中，即生物聚合物、色肽和蛋白质中，研究了无序体系中(生物)化学反应的基本步骤，例如在环境影响下的液体、瞬变结构。研究超短X射线脉冲的激光致密源以及X射线靶和光学部件的新概念是这项工作的一个重要方面，这项工作是与参加优先方案的各小组密切合作开展的。