Dresden 2011 – wissenschaftliches Programm
A 26.40: Poster
Donnerstag, 17. März 2011, 16:00–18:30, P2
Twin-configuration of xenon clusters observed in single shot imaging experiments at FLASH — •D Rupp1, M Adolph1, T Gorkhover1, S Schorb1,4, H Thomas1, D Wolter1, R Hartmann2, N Kimmel2, C Reich2, L Strüder2, R Treusch3, T Möller1, and C Bostedt1,4 — 1IOAP, TU Berlin — 2MPI Hll, München — 3FLASH/DESY, Hamburg — 4SLAC, Stanford
Intense, short laser pulses in the x-ray regime from free-electron lasers (FELs) hold great promise for single-shot single-particle imaging down to individual molecules. We performed first scattering experiments on individual free xenon nanoclusters with high intense soft x-ray laser pulses from FLASH-FEL3 using novel high performance pnCCDs2.
With less than one cluster in the laser focus, the diffraction patterns revealed three different geometrical configurations. The by far most frequent patterns of concentric rings reflect the event of a single cluster in focus, followed by a double-slit like pattern from a twin cluster configuration with two clusters in direct contact (∼ 1%) and a fine structured interference pattern similar to Newton rings from two clusters one after the other at µm distance (∼ 0.1%).
The twin clusters were so far not expected to be generated in gas expansion sources. Mass spectroscopy is not capable to identify them, only single shot scattering experiments can reveal their presence. Simulations of conceivable parameters as different orientation to the beam, sizes, and degree of fusion allow to explain all observed patterns. We discuss formation schemes and possible experimantal applications of twin clusters.