Analytische Chemie
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Simulates X-ray and Neutron scattering patterns from arbitrary shapes defined by STL files.
Features:
- Uses multithreading to compute a number of independent solutions, then uses the variance of the results to estimate an uncertainty on the output.
- Can be launched from the command line using an excel sheet to define settings, or from a jupyter notebook.
- Outputs scattering patterns in absolute units if the contrast is set.
- A Gaussian size distribution is available, where the relative scaling of objects for each repetion can be varied. Recommended to be used with limited width (max. 10%) to avoid artefacts.
- Writes results with settings to an archival HDF5 file.
Application examples:
This software has been used in several studies to date. For example, it has been used here to simulate a model scattering pattern for a cuboid shape, which was then fed forward into the McSAS3 analysis program for analyzing scattering patterns of polydisperse cuboids. A second use is here, where it was used for the modeling of flattened helices. In this paper, scattering pattern features could be matched with particular morphological changes in the structure. Lastly, this paper has an example where it was used to validate the analytical analysis model, and explore the realistic limits of application of the analytical model.
Excelling in brevity but lacking in applicability, the 2011 EU nanomaterial definition has become a source of anguish for scientists and industry alike. Repeated pleas and discussions with our own envoy have demonstrated the strength of their resolve: this definition is unlikely to change. Manufacturers of many materials (cosmetics, pigments, foodstuffs, etc.) will have to characterise and label all their products accordingly, a task still impossible for lack of a clear metrological approach towards this goal. Therefore, the onus has fallen on the scientists to come up with a practicable measurement technique allowing inexpensive classification covering large swathes of the material landscape. Small-angle X-ray Scattering (SAXS) probes the size range in question, and can - with due care - deliver a bulk-averaged volume-weighted size distribution. Like any other real-world measurement method, however, it is not (and can never be) a universal solution. This presentation will clarify the SAXS technique, provide several application examples for nanomaterial characterisation, and will detail the limitations and pitfalls that accompany its abilities. At the end of this presentation, you will have the information to judge whether the technique is amenable to your materials or not.
Nanoscience, SAXS and you
(2017)
Everything SAXS
(2019)
Experimenting on MAUS
(2019)
After a colleague sent me a more useful measurement from a laboratory instrument than what I could get from the beamline, I knew it was time to reassess my life's choices. Over the course of several subsequent post-doc and permanent positions around lab instruments, I managed to refine a flexible, comprehensive methodology for data collection, correction and analysis which can be applied to many X-ray scattering investigations at the lab and at the synchrotron. With the help of friends at round places, this methodology was implemented and put into production, and has been delivering high-quality data since then. Now, we have almost all possible data corrections (for X-ray scattering) implemented, and are improving the hardware to deliver higher-quality metadata to enable the corrections to be performed to a higher accuracy.
Simultaneously, we have set up a mini-large facility at BAM with the MAUS, the Multi-scale Analyzer for Ultrafine Structures. The MAUS combines the freedom of a laboratory instrument, with the spectrum of users of a beamline: besides measuring our own samples, and performing our own machine and methodology developments, we have opened this instrument for collaboration with fellow scientists from within BAM and from external institutes and universities. Here, we provide a comprehensive support for these collaborations, guiding the user from concept to sample selection, to interpretation and analysis. In 2019, we have supported over 30 different projects this way, leading to seven co-authored publications involving the MAUS in that year alone. As the MAUS uses the latest iteration of our comprehensive measurement methodology, the data quality is unmatched by any other lab instrument, and fully traceable to boot.
The freedom of the laboratory allows for more proof-of-principle experimentation than what is possible at the synchrotron. Therefore, the MAUS provides a good first (and sometimes final) step towards many experimental materials science investigations, nicely complementing the capabilities of the synchrotron. If and when more flux is needed, the step to the synchrotron is now smaller than ever, in particular with the same method
X-ray generation
(2020)