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The ultrafast pulses of X-ray FELs allow high-resolution imaging of biological and other soft matter without limitations imposed by radiation damage. A collaboration between LLNL, University of Uppsala, SLAC, TU Berlin, and DESY has carried out high-resolution diffraction imaging of structures using single 25 fs duration, 32 nm wavelength pulses generated by FLASH at DESY. Our objects were placed in the focused FEL beam, with peak intensities up to 1014 W/cm2. The objects were heated to about 60,000 K by the pulse, but destruction only occurred after the pulse traversed the sample. We reconstructed images from the finely-sampled coherent diffraction patterns by phase retrieval using our Shrinkwrap algorithm. These show no evidence of the effects of the pulse on the structure. We also performed quantitative measurements of the explosion of test particles in the focused FEL pulse, by recording their diffraction patterns. No motion occurred during the pulse and we followed the evolution of the explosion with a novel holographic time-resolved technique. Our results confirm the basic principles of flash imaging and lend great confidence to achieving molecular imaging at future short-wavelength X-ray FELs.
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