Physics-based reconstruction algorithm for 3D atom probe microscopy

基于物理的 3D 原子探针显微镜重建算法

• 批准号: 232117566
• 负责人: Professor Dr. Guido Schmitz
• 金额: --
• 依托单位: Abteilung für Materialphysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/232117566?language=en
• 关键词: Physics; based; reconstruction; algorithm; 3D; Physics; based; reconstruction; algorithm; 3D

Atom probe tomography represents a method of 3D material analysis in outstanding resolution that follows an unusual functional principle: Single atoms are desorbed from the sample as ions, accelerated in strong electric fields, detected by a spatially resolving detector setup, and identified by their time of flight. Subsequent to the measurement, a 3D map of the spatial arrangement of the atoms is generated by a numeric reconstruction. Up to now, the established reconstruction algorithms are based on a simple geometric projection. This leads to unacceptable artifacts and limits the accuracy of spatial positioning to about 1 nanometre. The primary goal of the project is the design and exploration of a new reconstruction method that is based on the physically exact calculation of the ion trajectories. In a first phase of the project, the original idea of exactly calculating the electrical fields and the ion trajectories for a particular sample geometry and then matching them with the positions of the detector events was tested. In the course of these investigations, an additional principle was derived to determine the positions of the atoms unambigously. Now this principle shall be tested with different sample geometries. Remaining parameters of the reconstruction shall be optimized so that the correct sample shape and microstructure is reconstructed. The accuracy of the procedure should be improved. It should be investigated whether even the measurement of the atomic lattice structure becomes possible. The numerical efficiency of the algorithms should be sufficiently improved so that the reconstruction can be processed on small multi-kernel CPU cards. Finally a software should be developed that allows the practical processing of experimental data sets.

原子探针断层扫描代表了一种以杰出分辨率的3D材料分析的方法，遵循了一个不寻常的功能原理：单个原子从样品中解脱为离子，在强烈的电场中加速，通过空间解析检测器设置，并通过飞行时间确定。在测量之后，原子的空间排列的3D图由数字重建产生。到目前为止，已建立的重建算法基于简单的几何投影。这导致无法接受的伪影，并将空间定位的准确性限制为约1纳米。该项目的主要目标是基于离子轨迹的物理确切计算的新重建方法的设计和探索。在项目的第一阶段中，测试了精确计算特定样品几何形状的电场和离子轨迹的最初想法，然后测试了它们与检测器事件的位置相匹配。在这些调查过程中，得出了一个额外的原则，以确定原子的位置。 现在，该原理应以不同的样品几何形状进行测试。重建的剩余参数应进行优化，以便重建正确的样品形状和微观结构。该过程的准确性应提高。应该研究是否甚至可以测量原子晶格结构。算法的数值效率应得到充分提高，以便可以在小型多内核CPU卡上处理重建。最后，应该开发一个软件，以实验数据集的实际处理。