Bonn 2025 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 60: Precision Spectroscopy of Atoms and Ions VI (joint session A/Q)
Q 60.5: Vortrag
Donnerstag, 13. März 2025, 15:45–16:00, KlHS Mathe
High resolution spectroscopy of Mossbauer materials using Ptychography — •Ankita Negi1, Lars Bocklage1, Leon Merten Lohse1, Sven Velten1, Guido Meier2, Ralf Röhlsberger3, and Christina Brandt4 — 1Deutsches Elektronen Synchrotron, Hamburg, Germany — 2Max Planck Institute for the structure and dynamics of matter, Hamburg, Germany — 3Friedrich Schiller Universität Jena, Jena, Germany — 4Universität Greifswald, Greifswald, Germany
Mössbauer spectroscopy is a technique for measuring atomic-level magnetic and chemical properties of materials. The "Mössbauer effect" allows nuclei to absorb or emit gamma radiation without losing energy to the lattice. Advances in synchrotron sources have enabled measurements of nuclear resonant scattering (NRS) of synchrotron gamma-ray pulses, offering better sensitivity and faster data collection compared to spectroscopy with traditional radioactive sources. However, extracting spectral information from a single time-domain NRS measurement is challenging and requires extensive modeling. To address this, we modify the setup and use multiple overlapping NRS measurements to extract both the transmission spectrum and phase. Our approach, inspired by phase retrieval algorithms in ptychography, frames the problem as a one-dimensional phase retrieval. We demonstrate the robustness of our method with 57Fe-enriched samples, showing that, unlike traditional Mössbauer spectroscopy, our technique overcomes bandwidth limitations of gamma-ray sources, offering new possibilities for research with modern X-ray sources and other Mössbauer isotopes.
Keywords: Ptychography; Phase retrieval; Nuclear resonant scattering; Mössbauer physics; X-ray spectroscopy