Berlin 2001 – wissenschaftliches Programm

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A: Atomphysik

A 1: Posters Monday (Cluster, Atoms in Fields)

A 1.8: Poster

Montag, 2. April 2001, 12:30–15:00, AT3

Ionic Recoil Energies in the Coulomb Explosion of Metal Clusters — •Silvio Teuber, Tilo Döppner, Thomas Fennel, Josef Tiggesbäumker, and Karl–Heinz Meiwes–Broer — Universität Rostock, FB Physik, Universitätsplatz 3, 18051 Rostock

The interaction of small metal clusters with intense laser fields (up to 10¹⁶ W/cm²) results in multiply charged ions. A strong enhancement of the charging process is observed when the laser frequency couples to the plasmon energy of the cluster, i.e., for a longer laser pulse width [1]. For gold, atomic charge states up to z=20 are detected at 600 fs and 1.5×10¹⁵ W/cm². The recoil energy distribution of the atomic fragment ions is measured for clusters of different metals varying the cluster size and the laser pulse width. Kinetic energies up to 180 keV are found in the case of large lead clusters. However, both the average and the maximum recoil energies decrease with laser pulse width. Thus, the enhanced charging efficiency for longer pulse widths is not reflected in the kinetic energy spectra. This behavior is in agreement with molecular dynamics calculations we have performed.

[1] L. Köller, M. Schumacher, J. Köhn, S. Teuber, J. Tiggesbäumker, K.–H. Meiwes–Broer. Phys. Rev. Lett., 82(19):3783–3786,1999.