Berlin 2005 – wissenschaftliches Programm
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O: Oberflächenphysik
O 5: Zeitaufgelöste Spektroskopie I
O 5.4: Vortrag
Freitag, 4. März 2005, 11:30–11:45, TU EB107
Photoemission from surface states using higher harmonic radiation — •Andrea Melzer1, Jinxiong Wang1, Alvaro Wulff1, Martin Weinelt2, and Thomas Fauster1 — 1Lehrstuhl für Festkörperphysik, Universität Erlangen-Nürnberg, Staudtstr. 7, D-91058 Erlangen — 2Max-Born-Institut, Max-Born-Str. 2A, D-12489 Berlin
Photon energies up to 45 eV are generated by focussing pulses from a multipass amplifier into argon. The laser provides pulses with 1.4 mJ energy at 770 nm wavelength at a repetition rate of 1 kHz. The pulse length is 30 fs leading to an intensity of ∼ 5 × 1014 W/cm2 at the focus. A grating monochromator with two interchangable toroidal gratings (250 and 950 lines/mm) is used to select the individual harmonics. Photoelectron spectra from surface states on fcc(111) surfaces are measured to characterize the photon energy, linewidth, polarization, intensity, and pulse length of the higher harmonic photon source. One-photon photoemission spectra can be recorded at gas pressures below 10 mbar with no detectable pressure increase in the ultrahigh vacuum chamber of the electron spectrometer.