Convergent-beam diffraction of ultra-short hard X-ray pulses focused by a capillary lens

We report the generation of diffraction patterns using X-ray pulses from a fs-laser plasma focused by an X-ray capillary lens to a spot size smaller than 100 μm. A thin moving iron tape is irradiated at 10 Hz with 200 mJ/130 fs titanium–sapphire laser pulses. Fe Kα (λ= 0.194 nm) radiation emitted from the rear side of the tape is focused to a spot by the capillary lens resulting in an intensity enhancement of about 1600. The ability of this system to effectively allow diffraction from samples of micron size is demonstrated by producing well-illuminated diffractograms from a Si(111) crystal with good signal to noise ratio obtained in only about 10 s. The different path lengths of propagation in the lens induce an angle-encoded delay of the converging X-ray pulse and thus provide the possibility of realizing a novel ultra-fast streak camera. PACS 52.59.Px; 52.38.Ph; 41.50.+h; 61.10.Nz