Hamburg 2009 – wissenschaftliches Programm

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A: Fachverband Atomphysik

A 38: Atomic Clusters IV

A 38.4: Vortrag

Freitag, 6. März 2009, 14:45–15:00, VMP 6 HS-C

Directed Electron Emission from Resonantly Excited Metal Nanoparticles — •Johannes Passig, Thomas Fennel, Xuan Truong Nguyen, Slawomir Skruszewicz, Josef Tiggesbäumker, and Karl-Heinz Meiwes-Broer — Institut für Physik, Universität Rostock, www.physik.uni-rostock.de\cluster

Experiments on metal particles exposed to intense ultrashort dual laser pulses reveal a strong asymmetric electron emission giving electron kinetic energies of up to 1.3 keV in the direction of the laser polarization axis. Conventional hydrodynamical or purely coulomb driven expansion processes fail to explain the kinetic energy values and the asymmetry in the electron emission. The energy transfer from the laser field to the fast electrons can be assigned to rescattering processes of weakly bound electrons in the resonant driven plasmon field, called SPARC [1]. Recently, the scattering of electrons in the mean field potential was identified as an alternative mechanism for the electron acceleration, particularly in Xe-clusters [2]. The influence of the particle size, laser intensity and pulse delay time on the observed electron emission is discussed in the context of both theoretical models.

[1] T. Fennel et al., Phys. Rev. Lett. 98(14), 2007 [2] U. Saalmann et al., Phys. Rev. Lett. 100(13), 2008