Abstract
Fluctuation X-ray scattering (FXS) is an emerging experimental technique in which solution scattering data are collected using X-ray exposures below rotational diffusion times, resulting in angularly anisotropic X-ray snapshots that provide several orders of magnitude more information than traditional solution scattering data. Such experiments can be performed using the ultrashort X-ray pulses provided by a free-electron laser source, allowing one to collect a large number of diffraction patterns in a relatively short time. Here, we describe a test data set for FXS, obtained at the Linac Coherent Light Source, consisting of close to 100 000 multi-particle diffraction patterns originating from approximately 50 to 200 Paramecium Bursaria Chlorella virus particles per snapshot. In addition to the raw data, a selection of high-quality pre-processed diffraction patterns and a reference SAXS profile are provided.
Highlights
Background & SummaryFluctuation X-ray scattering (FXS) studies extend traditional small angle X-ray scattering (SAXS)methods by using X-ray snapshot with exposure times so short that the ensemble of illuminated particles can be well approximated as frozen in time and space
The resulting scattering patterns are no longer angularly isotropic, but instead exhibit small intensity fluctuations around the mean SAXS intensity[1,2]. Angular correlations of these intensity fluctuations can be directly related to the underlying molecular structure of the sample, providing much more information than traditional 1D SAXS curves[3]
Ijðq; φÞIjðq[0]; φ þ where N is the total number of diffraction patterns, q and q' are the magnitudes of the scattering vectors, and φ and φ + Δφ are the corresponding angular coordinates describing the intensity Ij(q, φ) of the jth scattering pattern recorded on the detector
Summary
Fluctuation X-ray scattering (FXS) studies extend traditional small angle X-ray scattering (SAXS). The resulting scattering patterns are no longer angularly isotropic, but instead exhibit small intensity fluctuations around the mean SAXS intensity[1,2] Angular correlations of these intensity fluctuations can be directly related to the underlying molecular structure of the sample, providing much more information than traditional 1D SAXS curves[3]. Previous work has shown that the signal to noise ratio (SNR) of such data is independent of the number of particles per shot[5] when the particles are in a vacuum, the relationship between number of particles and SNR in the presence of large buffer and detector backgrounds has not yet been studied In this communication, we describe unprocessed, experimental multi-particle scattering data from which an FXS correlation data set can be derived. The data are deposited at the CXIDB9 in the form of hdf[5] and xtc files
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