Year: 2012
Type: preprint
Abstract: Single-particle imaging experiments of biomolecules at x-ray free-electron lasers (XFELs) require processing of hundreds of thousands (or more) of images that contain very few x-rays. Each low-flux image of the diffraction pattern is produced by a single, randomly oriented particle, such as a protein. We demonstrate the feasibility of collecting data at these extremes, averaging only 2.5 photons per frame, where it seems doubtful there could be information about the state of rotation, let alone the image contrast. This is accomplished with an expectation maximization algorithm that processes the low-flux data in aggregate, and without any prior knowledge of the object or its orientation. The versatility of the method promises, more generally, to redefine what measurement scenarios can provide useful signal in the high-noise regime.
Source: arXiv (Cornell University)
Institutions: Cornell University, Cornell High Energy Synchrotron Source
Language: English
Subfield: Radiation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: G1488452202, G222768804, G2371548206, G262532246, DEVELOPMENT AND APPLICATIONS OF PHOTOSENSITIVE DEVICE SYSTEMS TO STUDIES OF BIOLOGICAL AND ORGANIC MATERIALS, G2855871686, G303061748, G3107766857, G367921431, G3976199993, Operation of the Cornell High Energy Synchrotron Source (CHESS), G4235786860, G4581610328, G4654690619, G5570207115, G5825187129, G8925327636, G969889393
OpenAlex ID: W2951470056