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。它特别适合于样品中所有化学元素的成像和分析，没有偏置，具有同等的灵敏度。在FAU，我们的目标是走在原子探测器断层扫描研究的前沿。这包括内部开发的具有特殊功能的系统。直到最近，APT排除了由于所使用的不锈钢腔体污染而导致的氢的成像和分析。内部开发的系统包括一个带有钛内部和腔体的高端仪器，导致了直接检测氢1的超低氢背景。该仪器是世界上第一个也是目前唯一一个实现这一目标的仪器。它可以为所有化学元素提供同等灵敏度的成像和分析。这对于氢经济材料的研究尤为重要。在这项提议中，我们寻求将这种超低氢原子探测系统升级到最先进的激光辅助场蒸发系统，并配备足够的数字前端探测器。这将有多种用途。首先，它将使非导电材料中氢的分析成为可能，并极大地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检测效率，这在激光辅助原子探针断层扫描中尤其普遍，从而提高分析精度。第三，它将使我们能够以高检测效率(占所有原子的80%)分析非导电材料，这是对我们现有仪器的补充，现有仪器提供&lt；40%的检测效率，尽管质量分辨率很高。升级包括：(I)可调谐的深紫外飞秒激光器，最小波长为&lt；300 nm，脉冲能量为&gt；1000 pJ，脉冲重复率为&gt；200 kHz，包括用于衍射限制聚焦和光斑定位的光学元件。(Ii)一个延迟线探测器(探测头、高压电源和前置放大器)，至少有一条冗余延迟线，每个延迟线终点至少有一个通道采用≥2.5Gsa/S/ch直接数字化。这里申请的原子探测激光升级将在一汽材料研究的广阔研究环境中使用。我们的起点是通用材料属性研究所(WW1)，在那里，原子探测器迷人的可能性被非常有利可图地用于不同领域(例如，轻质建筑材料、催化、粒子技术)，并与我们的合作伙伴(TU Wien、MU Leoben/Uni Innsbruck、Paul Scherrer Institute、Oak Ridge National Lab等)合作。原子探测器的升级还将继续丰富FAU重要研究所的研究，如中央新材料和工艺技术研究所ZMP，以及专注于可再生能源材料研究的埃尔兰根-纽伦堡亥姆霍兹研究所。

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.