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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, 4×10 13 W cm -2 pulse, containing 10 12 photons at 32 nm wavelength, produced a coherent diffraction pattern from a nanostructured 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 is reconstructed at the 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. © 2006 Nature Publishing Group.

We describe a camera to record coherent scattering patterns with a soft-x-ray free-electron laser (FEL). The camera consists of a laterally graded multilayer mirror, which reflects the diffraction pattern onto a CCD detector. The mirror acts as a bandpass filter for both the wavelength and the angle, which isolates the desired scattering pattern from nonsample scattering or incoherent emission from the sample. The mirror also solves the particular problem of the extreme intensity of the FEL pulses, which are focused to greater than [10.sup.14] W/[cm.sup.2]. The strong undiffracted pulse passes through a hole in the mirror and propagates onto a beam dump at a distance behind the instrument rather than interacting with a beam stop placed near the CCD. The camera concept is extendable for the full range of the ftmdamental wavelength of the free electron laser in Hamburg (FLASH) FEL (i.e., between 6 and 60rim) and into the water window. We have fabricated and tested various multilayer mirrors for wavelengths of 32, 16, 13.5, and 4.5 nm. At the shorter wavelengths mirror roughness must be minimized to reduce scattering from the mirror. We have recorded over 30,000 diffraction patterns at the FLASH FEL with no observable mirror damage or degradation of performance. OCIS codes: 040.1490, 030.1670, 050.1940, 140.2600, 340.7470, 310.1210.

Author(s): Henry N. Chapman (corresponding author) [1, 2]; Stefan P. Hau-Riege [1]; Michael J. Bogan [1]; Saša Bajt [1]; Anton Barty [1]; Sébastien Boutet [1, 3, 4]; Stefano Marchesini [1, [...]

A multistep approach to biomolecular assembly is presented, which combines scanning probe nanolithography (SPN) with chemoselective protein-to-surface linkers to create nanometric chemical templates for fabricating virus arrays. The assembly of these arrays introduces unique target chemical groups on the virus surface and design a chemoselective linker and reaction scheme to covalently bind the virus onto a patterned chemical template created by SPN.

We performed a direct side-by-side comparison of a Shack-Hartmann wave-front sensor and a phase-shifting interferometer for the purpose of characterizing large optics. An expansion telescope of our own design allowed us to measure the surface figure of a 400-mm-square mirror with both instruments simultaneously. The Shack-Hartmann sensor produced data that closely matched the interferometer data over spatial scales appropriate for the lenslet spacing, and much of the [is less than]20-nm rms systematic difference between the two measurements was due to diffraction artifacts that were present in the interferometer data but not in the Shack-Hartmann sensor data. The results suggest that Shack-Hartmann sensors could replace phase-shifting interferometers for many applications, with particular advantages for large-optic metrology. OCIS codes: 120.3180, 120.3930, 010.7060.

Presents a multistep approach to biomolecular assembly which combines scanning probe nanolithography with chemoselective protein-to-surface linkers to create nanometric chemical templates for fabricating virus arrays. Immobilization of 11-mercaptoundecanoic acid on a trityl chloride resin through the selective formation of thioether bond to the solid-support; Creation of the nanometric chemical templates of the amine terminated alkanethiol.