Global ETD Search

31	Vibrational relaxation and dephasing of Rb2 attached to helium nanodroplets Grüner, Barbara, Schlesinger, Martin, Heister, Philipp, Strunz, Walter T., Stienkemeier, Frank, Mudrich, Marcel January 2011 (has links) The vibrational wave-packet dynamics of diatomic rubidium molecules (Rb2) in triplet states formed on the surface of superfluid helium nanodroplets is investigated both experimentally and theoretically. Detailed comparison of experimental femtosecond pump–probe spectra with dissipative quantum dynamics simulations reveals that vibrational relaxation is the main source of dephasing. The rate constant for vibrational relaxation in the first excited triplet state 13Σ+g is found to be constant γ ≈ 0.5 ns−1 for the lowest vibrational levels v [less, similar] 15 and to increase sharply when exciting to higher energies. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich. info:eu-repo/classification/ddc/540 ddc:540
32	Brillouin Propagation of Cold Atoms - Velocity-Matching or Mechanical Resonance? Scoggins, Casey Clark 05 August 2022 (has links) No description available. Optics Physics Brillouin brillouin propagation cold atoms optical lattice ratcheting directed ratcheting velocity matching velocity-matching velocity matching angled probe pump-probe spectroscopy off-axis probe mechanical resonance rubidium 85 dissipative bali samir casey scoggins brillouin feature angle error SAS spectroscopy
33	Constructing and Commissioning HELIOS – A High Harmonic Generation Source for Pump-Probe Measurements with sub 50 fs Temporal Resolution : The Development of Experimental Equipment for Extreme Ultraviolet Spectroscopy Terschlüsen, Joachim A. January 2016 (has links) This thesis presents HELIOS, an in-house laboratory for time-resolved pump-probe spectroscopy with extreme-ultraviolet (XUV) probe radiation. A wide span of pump wavelengths can be generated using commercial laser equipment while XUV probe radiation is generated via a high harmonic generation process in a noble gas delivering probe photons with energies between 20 eV and 72 eV. The XUV beam path features a time-preserving monochromator and was constructed and built in-house. HELIOS features an overall time resolution of about 50 fs when using 800 nm pump and 41 eV probe photons. An energy resolution of 110 meV at 41 eV photon energy can be achieved. HELIOS features two beamlines. One µ-focus beamline with an XUV focal size of about 20 µm can be used with experiments that require such a small XUV focal size as well as with different end stations. The other beamline features a semi-permanently mounted end station for angle-resolved photoelectron spectroscopy under ultra-high vacuum conditions. Experiments demonstrating the usability of HELIOS and the two beamlines are presented. A pump-probe measurement on graphene demonstrates the capability of determining a large part of the k-space in only one measurement due to the use of an ARTOF angle-resolved time-of-flight electron spectrometer. A non-angle-resolved pump-probe measurement on the conducting polymer PCPDTBT demonstrates the high signal-to-noise ratio achievable at this beamline in non-angle-resolved photoelectron-spectroscopy pump-probe measurements. The usability of the µ-focus beamline is demonstrated with time-resolved measurements on magnetic samples employing an in-house-designed spectrometer. These experiments allow the retrieval of element-specific information on the magnetization within a sample employing the transversal magneto-optical Kerr effect (T-MOKE). Additionally, a Fourier transform spectrometer for the XUV is presented, the concept was tested at a synchrotron and it was used to determine the longitudinal coherence of the XUV radiation at HELIOS. Angle-resolved time-of-flight Angle resolved time of flight ARTOF ARPES tr-ARPES fs fs resolution Fourier transform spectrometer Fourier-transform spectrometer Fourier transform spectroscopy Fourier-transform spectroscopy FTS gas cell high harmonic generation laser liquid jet monochromator HELIOS HHG off-plane mount off plane mount OPA optical parametric amplifier PCPDTBT pulse shaping pump probe pump-probe measurements pump-probe measurements pump-probe spectroscopy pump-probe spectroscopy Rowland spectrometer time-of-flight spectrometer time of flight spectrometer TOF time-resolved spectroscopy time resolved spectroscopy time-resolved experiments time resolved experiments T-MOKE tr-PES PES photoelectron spectroscopy transverse magneto optical Kerr effect transverse magneto-optical Kerr effect ultrafast ultra-high vacuum ultra high vacuum UHV XUV VUV X-rays Permalloy magnetization dynamic
34	Femtosekunden Photolyse von Diiodmethan in überkritischen Fluiden: Konkurrenz zwischen Photodissoziation und Photoisomerisierung / Femtosecond Photolysis of Diiodomethane in Supercritical Fluids: Competition between Photodissociation and Photoisomerisation Grimm, Christian 05 November 2003 (has links) No description available. Mathematics and Computer Science Käfigeffekt Femtochemie unimolekulare Reaktionen Photodissoziation Photoisomerisierung Diiodmethan Laserspektroskopie Pump-Probe-Spektroskopie überkritische Fluide Schwingungsenergietransfer Orientierungsrelaxation 540 Chemie cage effect femtochemistry unimolecular reactions photodissoziation photoisomerization diiodomethane laser spectroscopy pump probe spectroscopy supercritical fluids vibrational energy transfer orientational relaxation 35.16 35.13 35.25 SI 000: Photochemie Strahlungschemie SIL 000: Laser-Chemie {Strahlungschemie}
35	Photolytischer Käfigeffekt von Dihalomethanen in überkritischen Lösungsmitteln / Photolytic cage effect of dihalomethanes in supercritical solvents Zerbs, Jochen 02 November 2005 (has links) No description available. 540 Chemie Mathematics and Computer Science photolytischer Käfigeffekt Diiodmethan Bromiodmethan Pump Probe Spektroskopie überkritische Fluide Schwingungsenergierelaxation Orientierungsrelaxation molekulardynamische Simulationen radiale Verteilungsfunktionen lokale Dichtevergrößerung photolytic cage effect diiodomethane bromoiodomethane pump probe spectroscopy supercritical fluids vibrational energy relaxation orientational relaxation molecular dynamics simulations radial distribution functions local density enhancement 35.13 35.16 35.22 SD 000: Physikalische Chemie SBC 000: Chemie bei hohen Drucken SIL 000: Laser-Chemie {Strahlungschemie} SIC 000: Radiolyse {Photochemie}
36	Photodissoziation von Polyhalogenmethanen in Fluiden: Kurzzeitdynamik und Mechanismen / Photodissociation of polyhalomethanes in fluids: Ultrafast dynamics and mechanisms Wagener, Philipp 29 April 2008 (has links) No description available. 540 Chemie Mathematics and Computer Science photolytischer Käfigeffekt Polyhalogenmethane Ultrakurzzeitdynamik Photodissoziation Photoisomerisierung Pump Probe Spektroskopie überkritische Fluide Schwingungsenergierelaxation charge-transfer-Komplex lokale Dichtevergrößerung Photoionisation Solvatation freies Elektron Diffusion geminale Rekombination CTTS-Komplex photolytic cage effect polyhalomethanes ultrafast dynamics photodissociation photoisomerization pump probe spectroscopy supercritical fluids vibrational energy transfer charge-transfer complex local density enhancement photoionisation solvationdynamics of free electron diffusion geminate recombination CTTS-complex 35.13 35.16 35.22 SD 000: Physikalische Chemie SBC 000: Chemie bei hohen Drucken SIL 000: Laser-Chemie {Strahlungschemie}

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