Scattering of the forward-shock synchrotron emission by a relativistic outflow located behind the leading blast-wave may produce an X-ray emission brighter than that coming directly from the forward-shock and may explain four features displayed by Swift X-ray afterglows: flares, plateaus (slow decays), chromatic light-curve breaks, and fast post-plateau decays. For a cold scattering outflow, th...

In recent years there has been a growing interest in the application of X-ray scattering techniques to biomolecules in solution. At NSLS, a new undulator-based beamline, X9, has been constructed to address the oversubscribed user demand for X-ray scattering. Beamline X9 has the capability to perform small/wide-angle X-ray scattering (SAXS/WAXS) all in one single instrument. This is accomplished...

Dark-field images are formed from x-ray small-angle scattering signals. The small-angle scattering signals are particularly sensitive to structural variation and density fluctuation on a length scale of several tens to hundreds of nanometers, offering a unique contrast mechanism to reveal subtle structural features of an object. In this study, based on the principle of energy conservation, we d...

We report here a multiple-reflection type ultra-small-angle x-ray-scattering apparatus constructed according to the principle proposed by Bonse and Hart. The ultra-small-angle x-ray scattering technique enables us to investigate the distribution of solutes or particles in turbid systems, which could not be studied by the conventional light-scattering and microscopic methods. By this method, the...

We report a comparison of high resolution inelastic x-ray Brillouin scattering to coherent inelastic neutron scattering for amorphous deuterated polybutadiene, done for one temperature in the glass phase and another one in the melt. The x-ray scattering proves to be by far the better technique for such a polymer within its present resolution bounds. The neutron scattering allows one to extend t...

100 ps time-resolved X-ray solution-scattering capabilities have been developed using multilayer optics at the beamline NW14A, Photon Factory Advanced Ring, KEK. X-ray pulses with an energy bandwidth of DeltaE/E = 1-5% are generated by reflecting X-ray pulses (DeltaE/E = 15%) through multilayer optics, made of W/B(4)C or depth-graded Ru/C on silicon substrate. This tailor-made wide-bandwidth X-...

the internal structure of dna-ctab and dna-ddab is investigated by a small angel x- ray scattering(saxs) instrument. hexagonal packing of dna was observed for dna complex with ctab, and for ddabcomplex is observed lamellar structure. variations in the internal spacing and degree of long-range ordering aredependent on both surfactant type and concentrations of added salt. when we increased the a...

We present a non-resonant inelastic x-ray scattering study at the carbon Kedge on aligned poly[9,9-bis(2-ethylhexyl)-fluorene-2,7-diyl] and show that the x-ray Raman scattering technique can be used as a practical alternative to x-ray absorption measurements. We demonstrate that this novel method can be applied to studies on aligned π-conjugated polymers complementing diffraction and optical st...

The use of anomalous X-ray scattering to obtain the first differences and partial structure factors normally obtained with isotopic substitution neutron diffraction is described and compared with the neutron technique. Both the problems associated with the X-ray technique and the situations in which it is highly valuable are discussed. The availability of tunable, intense synchrotron radiation ...

We use published ROSAT observations of the X-ray Nova V1974 Cygni 1992 to test a model for interstellar dust grains consisting of a mixture of carbonaceous grains and silicate grains. The time-dependent X-ray emission from the nova is modelled as the sum of emission from a ONe white dwarf plus a thermal plasma, and X-ray scattering is calculated for a dust mixture with a realistic size distribu...