Single-shot coherent diffraction imaging using VUV-FEL

At the FLASH free-electron laser facility at DESY in Hamburg, an international team of scientists recently published the first data on diffraction imaging of a non-crystalline sample. Theoretically, a single X-ray pulse, if it is extremely bright and perfectly coherent, can produce a diffraction pattern from a large macromolecule, a virus or a cell (for example, see, "Potential for biomolecular imaging with femtosecond X-ray pulses", R. Neutze et al., Nature, 406, 752-757 (2000)). In the present experiment, the team tested a laser pulse with 25 fs, 41013 W/cm²/pulse, containing 1012 photons at 32 nm wavelength, and obtained a coherent diffraction pattern from a nanostructured non-periodic object before this exploded into a plasma at ca. 60,000 K. They employed a novel X-ray camera assured of single-photon detection sensitivity by filtering out parasitic scattering and plasma radiation. For more information, see the paper, "Femtosecond diffractive imaging with a soft-X-ray free-electron laser", H. N. Chapman et al., Nature Physics, published online 12 November 2006.