|Austin Akey||Harvard University||Measurement Science Workshop: The practice of a measurement technique is as important as the design of the instrument, and must be thoroughly studied for accurate measurements and consistent reporting. At present, Atom Probe Tomography is a well-developed technique with a rapidly-growing population of expert practitioners throughout the world; there is however significant variation in both the practice of APT and the reporting of data across this population. Given the ultimate goal in APT development of consistent, standards-less, absolute quantitative measurement of atomic-scale composition in three dimensions, the field requires tools to address these outstanding measurement science challenges. This workshop focuses on the use of Interlaboratory Studies as a tool to achieve these goals, featuring presentations on the design of these studies, ongoing work in this direction, and the needs of the broader scientific community including our colleagues in industry.|
|Brian Geiser||CAMECA, Inc.||Spatial Reconstruction Tutorial: To obtain useful structural composition information from atom probe data, it must be spatially reconstructed as accurately as possible. This discussion will present the basic ideas behind current reconstruction techniques. The strengths and weaknesses of some of the methods will be discussed, including the situations in which the techniques start to fail and some of the artifacts that result. Further techniques for improving the results of reconstructions and quantifying their accuracy will also be reviewed.|
|Karen Henry||Bechtel Marine Propulsion Corporation||Open Software Workshop: The software workshop will focus on programs, scripts, utilities, and software packages developed by individuals or groups to facilitate data analysis and/or data treatment to advance atomic-scale understanding of materials science processes. The workshop will consist of demonstrations by invited presenters, an open forum for new and experienced users to contribute 5-minute Flash Talks about a script, utility, or program a user or group finds useful for data analysis or data treatment and an open discussion about the software needs of the community.|
|Hugues Francois Saint Cyr||CAMECA, Inc.||IVAS Tutorial|
|John Henry Scott||National Institute of Standards and Technology||Sparse Data Sampling Overview: This tutorial will explore the advantages and pitfalls of using sparse data representations and related methods for reconstructing complete datasets from a limited number of measurements or observations. In favorable cases, near-perfect reconstructions of images or volumetric datasets are possible even when more than 90% of the data are missing or hidden. This result can be exploited to reduce the dose required during data acquisition. Examples using standard test data from the applied mathematics and computer science literature will be supplemented by additional real-world examples drawn from the fields of microscopy and microanalysis. We will also discuss the deep connections between the information content in an image and the constraints, assumptions, or a priori structure imposed by the image representation, and how these constraints can lead to powerful denoising algorithms. Finally, this survey will briefly cover the relatively new concept of compressed sensing, explain its relationship to the above topics, and review results in the field that provide solid, quantitative predictions of information recovery well past the limits of what was thought possible based on the Nyquist-Shannon sampling theorem. While some advanced mathematics will be mentioned and explained as needed during the talk, no prior knowledge of methods or jargon is required, and the surprising power and utility of these approaches can be appreciated based solely on the examples.|
|Tomas Silva Santisteban||Thermo Scientific||
Avizo™ Software Tutorial: This technical session will introduce the Avizo software and show how it can be used with atom probe related data sets. An introduction and overview of APT applications is followed by a live demonstration of a complete workflow of an atom probe data set within the software. The demonstration will show how to load the data, visualize it and perform an analysis, like filtering data by atomic numbers amongst others.
Paraphrasing William Horwitz, late champion and chronicler of Interlaboratory studies (ILS) in analytical chemistry, an ILS is a study in which several laboratories address the same issue under documented conditions, the results of which are compiled into a single report. Participants typically measure some quantity(ies) in some common set of materials, analyze the same set of data, or attack the same well-defined problem using their own approaches and data. There are four basic types of ILS: proficiency testing (PT), method evaluation, material characterization, and community performance. PT studies evaluate the competence of the participants, are by far the most abundant type of ILS, have well-defined codes of conduct, and are mostly provided by for-profit organizations. Method evaluation studies characterize well-defined measurement or data analysis procedures under real-world conditions and are typically sponsored (and/or mandated) by regulatory authorities. Material characterization studies are typically conducted by National Metrology Institutes – like NIST – and others as part of their reference material certification processes. Community performance studies are like PT but without the angst, seeking to understand the strengths and weaknesses of a community rather than those of the individual players within that community; they are often conducted by the community itself.
Tuesday June 12th and Wednesday June 13th from 4:15pm to 5pm (20 attendees max, each)
IVAS 101 or How to make the most out of your dataset using your favorite 3D reconstruction wizard?
Despite the efforts and research deployed, especially for the last 20 years, in terms of specimen preparation and instrumentation to improve Atom Probe Tomography (APT) on materials, the atomic reconstruction in three dimensions (3D) remains the most uncertain step as it relies on many modeling assumptions and individual paths for data processing. This tutorial aims at providing a systematic methodology to treat APT data, hunting down as many clues as possible and exploring many options from the Integrated Visualization and Analysis Software (IVAS), leading to the clearest representation of the reconstruction, even before being able to see the volume in 3D. This tutorial has been specially created for users new to the APT field or willing to accept that their current approach might be either rusty or incomplete.
The semiconductor industry has historically been known to drive innovation and push manufacturers to reach higher limits in technological milestones. Although Atom Probe Tomography (APT) has become a must-have characterization technique in this field, IVAS, the Integrated Visualization and Analysis Software, has not been used to its fullest by APT users to provide its best outcome. This tutorial should be beneficial to users who want to present their reconstructed volumes under their best angle and explore the data analysis space to their advantages. Dr. Hugues Francois-Saint-Cyr (CAMECA) and Dr. Andy Martin (GlobalFoundries) will share their views with users and help set the right expectations and moves on a 14-nm FinFET device which was graciously provided by researchers in the field of semiconductors .
 Pritesh Parikh et al., Three-Dimensional Nanoscale Mapping of State-of-the-Art Field-Effect Transistors (FinFETs), Microscopy and Microanalysis. 23 (2017), 916-925.
Approaching Perfection in Atomic Positioning: From Image Compression and k Factors to Dynamic Considerations
Alec Day (Sydney University) and Hugues Francois-Saint-Cyr (CAMECA Inc)
For historical and technological reasons, metallurgists were the first to adopt Atom Probe Tomography (APT) as a routine material characterization technique at the atomic scale. Pure and lightly alloyed metals are known to produce pole patterns on the desorption hit maps, as a result of the ions evaporating from faceted tip shapes. Although aberrations such as holes are observed in a fully dense material, experimental angles and distances between poles are evaluated with respect to the theoretical values to provide an Image Compression Factor (ICF). A precipitate-containing Al alloy and a steel will be treated using the Pole Indexing and ICF Fit option in IVAS 3.8. An additional step in the data reconstruction will be explored by the research led in APT at the University of Sydney , which will account for observed variations in the Image Compression Factor and k Factor as the tip is being consumed.
 Alec Day et al., Novel Crystallographic Framework for Reconstruction in APT, APT&M 2018.