Principles of x-ray diffraction microscopy

X-ray diffraction microscopy is an innovative method to reconstruct the electron density distribution from its x-ray diffraction intensity data with no need of sample crystallization. In experiments, it is essential that the whole region of a sample particle is illuminated with coherent x-rays, so that the x-ray diffraction intensity pattern has sensitivity to the sample structure in the wavelength spatial resolution. In the method, x-ray diffraction intensity patterns are sampled finely enough to satisfy the oversampling condition for solving the phase problem. The reconstruction of the sample structure from the diffraction intensity pattern is performed using an iterative method. An ambitious plan with future SASE FEL sources is under discussion, to measure snapshot images of sample structure in femto second time resolution. (author)