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Q: Fachverband Quantenoptik und Photonik

Q 35: Ultrakurze Laserpulse: Anwendungen 2

Q 35.2: Vortrag

Mittwoch, 16. März 2011, 14:45–15:00, SCH A01

Ultrafast electron kinetics in metals irradiated with femtosecond XUV laser pulses — •Nikita Medvedev^1,2 and Baerbel Rethfeld¹ — ¹Technical University of Kaiserslautern, Germany — ²CFEL at DESY, Hamburg, Germany

Metals irradiated with ultrashort laser pulses undergo a photoabsorption by electrons in conduction band and by ionization of deep atomic shells if the photon energy is sufficient. The relaxation of this excited nonequilibrium electron ensemble leads to photoemission, which can be detected experimentally, and to a lattice heating with further observable material modifications. We present a theoretical study of the excited electronic subsystem in solid aluminum irradiated with XUV (∼ 10 - 200 eV) femtosecond laser pulse (∼ 10 fs), as produced by the FLASH (free electron laser in Hamburg). The Monte Carlo method is extended to take into account the electronic band structure and Pauli’s principle for excited electrons, secondary ionization, Auger-decays [1,2]. The results show that excited electronic distribution has two branches: a low energy part as a slightly distorted Fermi-distribution and a long high energy tail. We compare the calculated electron distributions with the spectroscopy data obtained in first experiments with FLASH [3].

[1] N.Medvedev, B.Rethfeld, New J. Phys. 12, 073037 (2010)

[2] N.Medvedev, B.Rethfeld, AIP conf. Proc. 1278, 250 (2010)

[3] S. M. Vinko et al., Phys. Rev. Lett. 104, 225001 (2010)