Christoph Bostedt (SIMES Friday Seminar)

Date(s) - Apr 19 2013
11:00 AM - 12:30 PM

Shasta Room, Bldg 40, Room 361


Clusters in intense x-ray pulses

 Christoph Bostedt

Linac Coherent Light Source, SLAC National Accelerator Laboratory


Free-electron lasers deliver extremely intense femtosecond x-ray flashes opening the door for imaging single nanoscale objects in a single shot. All matter irradiated by the focused, intense x-ray pulses, however, will be transformed into a highly-excited non-equilibrium plasma within femtoseconds. During the x-ray pulse complex electron dynamics and the onset of atomic disorder will be induced. We have pioneered coincident imaging and spectroscopy techniques for investigating electronic and structural changes in atomic clusters irradiated at power densities exceeding 1017 W/cm2. Our data show that the scattering signal carries information about transient electronic states in the x-ray excited particles. Further, the energy absorption in the nanometer-scale samples depends on the cluster size since the Auger rates in the developing nanoplasma are changing during the femtosecond x-ray pulse. Recent single-shot experiments with hard x-rays yield insight into the crystalline order of the particles.