The next Imaging and Optical Physics (IOP) seminar will be held from 11 am on Tuesday, 9 April 2019, in Level 7 Conference Room of the School of Physics, the University of Melbourne (corner of Tin Alley and Swanston St, Parkville). The presenters will be Prof. Les Allen (Melbourne Uni) and Mr. Darren Thompson (CSIRO). The details of the talks are below.

11:00 - 11:30 am

Prof. Les Allen (the University of Melbourne)

Structure Retrieval at Atomic Resolution in the Presence of Multiple Scattering

Abstract:This talk will discuss the reconstruction of the projected electrostatic potential of a thick crystal at atomic resolution from experimental scanning transmission electron microscopy data recorded using a new generation fast-readout electron camera. This practical and deterministic inversion of the equations encapsulating multiple scattering that were written down by Bethe in 1928 removes the restriction of established methods to ultrathin (≲50 Å) samples.

11:30 am - 12:00  noon

Mr. Darren Thompson (CSIRO) 

3D Post-Reconstruction TIE-Hom Phase Retrieval for Multi-Material Objects 

Abstract:The TIE-Hom-3D phase-retrieval filter demonstrates quantitatively accurate and stable phase retrieval comparable to the projection-based 2D version of TIE-Hom with some modest noise-suppression improvements. Significant computational gains can be achieved using TIE-Hom-3D for multi-material samples with the requirement of only a single CT reconstruction. With material-specific phase retrieval performed on localized reconstructed sub-volumes, near-real-time phase retrieval may be possible utilizing localized TIE-Hom-3D method with appropriate computing resources.