Project P7: Impact experiments at high speeds and fragment distributions

远红外线观测显示，由于微米大小的尘埃颗粒，碎片盘表现出增强的热发射。尘埃物质的结构状态和热发射是由粒子和恒星风辐射（所谓的空间风化）之间的碰撞决定的。该项目的最终目标是在激光实验中模拟粒子碰撞和空间风化的影响，并通过高分辨率电子显微镜和光谱学表征结构损伤。基于这些数据，我们期望改进碎片盘模型，更好地理解碎片盘的观测数据。我们的初步工作令人印象深刻地证明了实验方法的可行性。在第一次对橄榄石的激光实验中，我们观察到典型的冲击效应（平面断裂和c位错）和空间风化现象（非晶化和纳米铁）的形成。该跨学科项目致力于优化和校准实验装置，以便在可变压力-温度条件下进行系统实验。这些实验将对与行星学有关的矿物（橄榄石、辉石、三辉石、FeNi相）进行。透射电子显微镜是检测和表征激光照射矿物缺陷的必要手段。该项目是对P6的补充，使用不同的技术、材料和参数范围，并将为P1、P2和P3模型提供输入。

Remote infrared observations reveal that debris disks exhibit an enhanced thermal emission due to micrometer sized dust particles. The structural state and the thermal emission of dust matter are determined by collisions between the particles and stellar wind irradiation (so-called space weathering). The ultimate goal of this project is to simulate the effects of particle collisions and space weathering in laser experiments and to characterize the structural damage by high-resolution electron microscopy and spectroscopy. Based on these data we expect to improve debris disk models and better understand observational data of debris disks. Our preliminary work demonstrates impressively the feasibility of the experimental approach. In first laser experiments on olivine we observed the formation of typical shock effects (planar fractures and c dislocations) and space weathering phenomena (amorphization and nano-Fe). This interdisciplinary project is devoted to optimize and calibrate the experimental setups such that systematic experiments can be carried out at variable pressure-temperature conditions. The experiments will be performed on planetologically relevant minerals (olivine, pyroxene, troilite, FeNi phases). The use of transmission electron microscopy is mandatory to detect and characterize the defects in laser-irradiated minerals. This project is complementary to P6, using different techniques, materials, and parameter ranges, and will provide input for models of P1, P2, and P3.