Year: 2022
Type: article
Abstract: Single-shot coherent diffraction imaging (CDI) is a powerful approach to characterize the structure and dynamics of isolated nanoscale objects such as single viruses, aerosols, nanocrystals and droplets. Using X-ray wavelengths, the diffraction images in CDI experiments usually cover only small scattering angles of a few degrees. These small-angle patterns represent the magnitude of the Fourier transform of the 2D projection of the sample's electron density, which can be reconstructed efficiently but lacks any depth information. In cases where the diffracted signal can be measured up to scattering angles exceeding ∼10°, i.e. in the wide-angle regime, some 3D morphological information of the target is contained in a single-shot diffraction pattern. However, the extraction of the 3D structural information is no longer straightforward and defines the key challenge in wide-angle CDI. So far, the most convenient approach relies on iterative forward fitting of the scattering pattern using scattering simulations. Here the Scatman is presented, an approximate and fast numerical tool for the simulation and iterative fitting of wide-angle scattering images of isolated samples. Furthermore, the open-source software implementation of the Scatman algorithm, PyScatman , is published and described in detail. The Scatman approach, which has already been applied in previous work for forward-fitting-based shape retrieval, adopts the multi-slice Fourier transform method. The effects of optical properties are partially included, yielding quantitative results for small, isolated and weakly interacting samples. PyScatman is capable of computing wide-angle scattering patterns in a few milliseconds even on consumer-level computing hardware, potentially enabling new data analysis schemes for wide-angle coherent diffraction experiments.
Language: English
Subfield: Radiation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Awards: G1580814116, G2547737128, G3285333993, StarkfeldNanophysik, G3505267072, Verbundprojekt 05K2016 - Nanoteilchenstruktur: Hochaufgelöste Struktur und Dynamik einzelner Nanoteilchen. Teilprojekt 2., SFB 1477: LichtMaterieWechselwirkung an Grenzflächen, G3730379932, G4002861216, Analyse und Kontrolle kollektiver, kohärenter und korrelierter Elektronendynamik in lasergetriebenen MetallNanostrukturen, G5620122118, G5908921700, G6075859995, G6488228673, Ionization dynamics of helium clusters and droplets in intense short-wavelength light pulses
OpenAlex ID: W4295720425