Hannover 2016 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MO: Fachverband Molekülphysik

MO 15: Femtosecond Spectroscopy 3

MO 15.6: Vortrag

Donnerstag, 3. März 2016, 12:30–12:45, f102

Femtosecond oxygen K-edge absorption spectroscopy of thymine — T. J. A. Wolf¹, R. Heilemann Myhre^1,2, H. Koch^1,2, A. Battistoni¹, N. Berrah³, P. H. Bucksbaum¹, R. Coffee⁴, S. Coriani⁵, G. Coslovic⁴, J. Cryan¹, R. Feifel⁶, K. Gaffney¹, J. Grilj⁷, T. Martinez^1,8, S. Miyabe¹, S. Möller⁴, M. Mucke⁹, A. Natan¹, R. Obaid³, T. Osipov⁴, O. Plekan¹⁰, A. Sage³, R. Squibb⁶, S. Wang¹, and •M. Gühr^1,11 — ¹PULSE, SLAC National Accelerator Laboratory and Stanford University, USA — ²Chemistry Dept., NTNU, Trondheim, Norway — ³Physics Dept., University of Connecticut, Storrs USA — ⁴LCLS, SLAC National Accelerator Laboratory, USA — ⁵Chemistry Dept., Universita' di Trieste, Italy — ⁶Physics Dept., Gotheborg University,Sweden — ⁷LSU, EPFL, Lausanne, Switzerland — ⁸Chemistry Dept., Stanford University, USA — ⁹Physics Dept., Uppsala University, Sweden — ¹⁰Syncrotrone Elettra, Trieste, Italy — ¹¹Physics and Astronomy, Universität Potsdam, Germany

We show first results of ultrafast soft x-ray absorption spectroscopy in the gas phase. After ultraviolet excitation to the ππ* state, the nucleobase thymine undergoes internal conversion to the nπ* and electronic ground state. We probe this nonadiabatic process using resonant absorption at the oxygen K-edge. We identify a UV induced bleach of the initially unoccupied π* states around 531 eV in the absorption spectrum. In addition, we observe an entirely UV generated absorption feature about 4.5 eV lower than the π* resonances, which we assign to a molecular nonadiabatic relaxation channel.