Showing papers by "Sébastien Boutet published in 2006"

Femtosecond diffractive imaging with a soft-X-ray free-electron laser

Abstract: Theory predicts that with an ultrashort and extremely bright coherent X-ray pulse, a single diffraction pattern may be recorded from a large macromolecule, a virus, or a cell before the sample explodes and turns into a plasma. Here we report the first experimental demonstration of this principle using the FLASH soft X-ray free-electron laser. An intense 25 fs, 4 x 10{sup 13} W/cm{sup 2} pulse, containing 10{sup 12} photons at 32 nm wavelength, produced a coherent diffraction pattern from a nano-structured non-periodic object, before destroying it at 60,000 K. A novel X-ray camera assured single photon detection sensitivity by filtering out parasitic scattering and plasma radiation. The reconstructed image, obtained directly from the coherent pattern by phase retrieval through oversampling, shows no measurable damage, and extends to diffraction-limited resolution. A three-dimensional data set may be assembled from such images when copies of a reproducible sample are exposed to the beam one by one.

Radiation driven collapse of protein crystals.

Abstract: During coherent X-ray diffraction measurements on crystals of ferritin at room temperature using monochromatic undulator radiation from the Advanced Photon Source, a sudden lattice contraction was observed following a characteristic latent period and ultimately leading to the collapse of the crystal. The progression of this collapse is analysed using a two-state Hendricks-Teller model. It reveals that 55% of the layers collapse by 1.6% before the crystal completely stops diffracting.

Ultrafast coherent diffraction imaging with x-ray free- electron lasers*

Abstract: The ultrafast pulses from X-ray free-electron lasers will enable imaging of non-periodic objects at near-atomic resolution [1, Neutze]. These objects could include single molecules, protein complexes, or virus particles. The specimen would be completely destroyed by the pulse in a Coulomb explosion, but that destruction will only happen after the pulse. The scattering from the sample will give structural information about the undamaged object. There are many technical challenges that must be addressed before carrying out such experiments at an XFEL, which we are doing so with experiments at FLASH, the soft-X-ray FEL at DESY.