title: Effectiveness of iterative algorithms in recovering phase in the presence of noise.
abstract: Inversion of coherent X-ray diffraction patterns allows the imaging of three-dimensional density distributions. The recovery of such shapes often requires application of iterative algorithms, such as Fienup's error reduction or hybrid input/output. Since the measurement of such a pattern records the intensity in reciprocal space, any errors due to noise will probably not have a straightforward impact on the final real-space result. In this paper, the effect of the types of noise common in coherent X-ray diffraction (CXD) experiments, counting statistics, scatter from alien particles and detector noise, on the recovered real-space density projection is explored by simulating a two-dimensional CXD pattern and adding noise. It is found that an R factor measuring the reproducibility between the best and second-best real-space result is a leading indicator of performance.
authors.affiliation: Department of Physics, University of Illinois, Urbana, IL 61801, USA. g.williams@physics.unimelb.edu.au
authors.forename: Garth
authors.initials: G
authors.lastname: Williams
authors.forename: Mark
authors.initials: M
authors.lastname: Pfeifer
authors.forename: Ivan
authors.initials: I
authors.lastname: Vartanyants
authors.forename: Ian
authors.initials: I
authors.lastname: Robinson
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D006046:Gold / Q000737:chemistry; D012815:Signal Processing, Computer-Assisted; D014961:X-Ray Diffraction / Q000379:methods*
chemical_list: D006046:Gold