arXiv subjects

D. K. Saldin

Publications and source records attributed to D. K. Saldin.

3 recordsLinked to original sources

arXiv2020

Reconstruction of 3D Image of Nanorice Particle from Randomly Oriented Single-Shot Experimental Diffraction Patterns Using Angular Correlation Method

We reconstructed intensities in Fourier space and electron densities in the real space for an azimuthally symmetric object Nanorice particle (Iron Oxide nanoparticle) exposed in the ultrashort, bright and coherent x-ray free electron laser (XFEL) pulses with random unknown orientations through the method of angular correlations among intensities appeared in ninety eight 2D diffraction patterns collected at Linac Coherent Light Source (LCLS).

physics.bio-ph↗

arXiv2007

Crystallography without crystals I: the common-line method for assembling a 3D intensity volume from single-particle scattering

We demonstrate that a common-line method can assemble a 3D oversampled diffracted intensity distribution suitable for high-resolution structure solution from a set of measured 2D diffraction patterns, as proposed in experiments with an X-ray free electron laser (XFEL) (Neutze {\it et al.}, 2000). Even for a flat Ewald sphere, we show how the ambiguities due to Friedel's Law may be overcome. The method breaks down for photon counts below about 10 per detector pixel, almost 3 orders of magnitude higher than expected for scattering by a 500 kDa protein with an XFEL beam focused to a 0.1 micron diameter spot. Even if 10**3 orientationally similar diffraction patterns could be identified and added to reach the requisite photon count per pixel, the need for about 10**6 orientational classes for high-resolution structure determination suggests that about ~ 10**9 diffraction patterns must be recorded. Assuming pulse and read-out rates of 100 Hz, such measurements would require ~ 10**7 seconds, i.e. several months of continuous beam time.

q-bio.BM↗

arXiv1998

Extending holographic LEED to ordered small unit cell superstructures

Following on the success of the recent application of holographic LEED to the determination of the 3D atomic geometry of Si adatoms on a SiC(111) p(3x3) surface, which enabled that structure to be solved, we show in this paper that a similar technique allows the direct recovery of the local geometry of adsorbates forming superstructures as small as p(2x2), even in the presence of a local substrate reconstruction.

cond-mat.mtrl-sci↗