Atom probe instrument for the imaging of hydrogen in materials – laser pulsing / detector upgrade

APT已被广泛用于研究一系列高强度结构合金、半导体材料和氧化物。它特别适合于对样品中的所有化学元素进行成像和分析，没有偏差，具有相同的灵敏度。在FAU，我们的目标是站在原子探针断层扫描研究的最前沿。这包括内部开发的具有特殊功能的系统。直到最近，由于所使用的不锈钢腔室的污染，APT排除了氢的成像和分析。内部开发的系统包括一个高端仪器，内部和腔室为钛合金，从而产生超低氢背景，用于直接检测氢1。该文书是第一个也是目前世界上唯一一个实现这一目标的文书。它可以以相同的灵敏度为所有化学元素提供成像和分析。这对于氢经济材料的研究尤为重要。在这个建议中，我们寻求这个超低氢原子探针系统升级到国家的最先进的激光辅助场蒸发与足够的数字前端检测器。这将达到多种目的。首先，它将允许分析非导电材料中的氢，并大大提高导电样品的数据产量。其次，它将提高非随机探测器命中的探测效率，这在激光辅助原子探针层析成像中特别普遍，因此提高了分析精度。第三，它将使我们能够以高检测效率（>所有原子的80%）分析非导电材料，这与我们现有的仪器相辅相成，尽管质量分辨率很高，但检测效率<40%。升级包括：（i）最小波长< 300 nm、脉冲能量> 1000 pJ和脉冲重复率> 200 kHz的可调谐深紫外fs激光器，包括用于衍射限制聚焦和光斑定位的光学器件。(ii)延迟线检测器（检测器头、高压电源和前置放大器），至少有一条冗余延迟线，每个延迟线端点至少有一个通道上的直接数字化≥ 2.5 GSa/s/ch。原子探针激光器升级申请将在FAU材料研究的广泛研究环境中使用。我们的出发点是通用材料性能研究所（WW 1），在那里，原子探针的迷人可能性在不同领域（例如轻质建筑材料、催化、颗粒技术）以及我们的合作伙伴（TU Wien、MU Leoben / Uni因斯布鲁克、Paul Scherrer研究所、橡树岭国家实验室等）都得到了非常有益的应用。原子探针的升级也将继续丰富FAU重要研究机构的研究，如中央新材料和工艺技术研究所（ZMP）和亥姆霍兹研究所（Helmholtz Institute Erlangen-Nuremberg），该研究所专注于可再生能源材料研究。

APT has been widely used to study a range of high-strength structural alloys, semiconductor materials and oxides. It is uniquely suited for the imaging and analysis of all chemical elements in a sample without bias and with equal sensitivity. At FAU we aim to be on the forefront of atom probe tomography research. This includes in-house developed systems with special capabilities. Up to recently, APT excluded the imaging and analysis of hydrogen due to contamination from the stainless-steel chambers used. The in-house developed systems include a high-end instrument with titanium interior and chamber, resulting in an ultra-low hydrogen background for direct detection of hydrogen1. This instrument is the first and currently only one world-wide to achieve this. It can provide imaging and analysis for all chemical elements with equal sensitivity. This is especially important for the research on materials for the hydrogen economy. In this proposal we seek the upgrade of this ultra-low H atom probe system to state-of-the-art laser assisted field evaporation with an adequate digital front-end detector. This will serve multiple purposes. Firstly, it will allow the analysis of hydrogen in non-conductive materials and greatly increase the data yield on conductive specimens. Secondly, it will improve the detection efficiency of non-random detector hits, which are especially prevalent in laser-assisted atom probe tomography and therefore increase the analysis accuracy. Thirdly, it will enable us to analyse non-conductive materials with high detection efficiency (> 80% of all atoms), complementary to our existing instrument, which provides < 40 % detection efficiency albeit at high mass resolution. The upgrade consists of: (i) a tuneable deep-UV fs laser with < 300 nm minimum wavelength, > 1000 pJ pulse energy and a pulse repetition rate > 200 kHz, including optics for diffraction limited focussing and spot positioning. (ii) A delayline detector (detector head, high voltage power supply and pre-amplifier) with at least one redundant delayline and direct digitization with ≥ 2.5 GSa/s/ch on at least one channel per delayline endpoint. The atom probe laser upgrade applied for here will used in a broad research environment of materials research at FAU. The starting point is the Institute for General Materials Properties (WW1), where the fascinating possibilities of the atom probe are used very profitably in different areas (e.g. lightweight construction materials, catalysis, particle technology) and together with our collaboration partners (TU Wien, MU Leoben / Uni Innsbruck, Paul Scherrer Institute, Oak Ridge National Lab and more). The atom probe upgrade will also continue to enrich research at important FAU institutes, such as the Central Institute for New Materials and Process Technology, ZMP, and the Helmholtz Institute Erlangen-Nuremberg, which focuses on materials research for renewable energies.