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Date: 2010-06-01 Time: 14:15 - 15:15 Place: K-space (Q-building, room Q179), Physics department, Sölvegatan, Lund, Sweden. About the speaker: Gerhard started his work at Brookhaven National Lab in the U.S. and joined the ESRF, France, in 1991 where he built the first beamline to operate at ESRF. In collaboration with other groups, he developed the X-ray photon correlation spectroscopy (XPCS), which exploits the coherent properties of synchrotron X-rays. He is now a senior scientist at HASYLAB at the Deutsches Elektronen-Synchrotron (DESY) in Hamburg, Germany, where he is involved in the development of coherence based techniques for free-electron laser sources. Gerhard received the ninth 2009 Arthur H. Compton Award together with o Simon Mochrie (Yale University, New Haven, U.S.) and Mark Sutton (McGill University in Montreal, Canada) for their work on coherent scattering. Abstract: The structure and dynamics of magnetic nanosystems is of both, fundamental and technologi cal interest. Ideally, one would like to probe magnetisation dynamics on a time scale of 100 femtoseconds (fs), with nanometre spatial resolution, while being able to do the measure ments element-specifically in order to account for the complex composition of actual mag netic media. Storage ring sources provide us with the necessary structural information while ultrafast magnetic scattering experiments require flashes of resonantly tuned soft X-rays that can be anticipated given the current construction of X-ray free-electron lasers (FEL) in Stan ford, CA, Hyogo, Japan and Hamburg, Germany. The FLASH facility in Hamburg already provides uniquely intense coherent short pulses in the EUV energy range with the shortest fundamental wave length l=6.1 nm. Using the fundamental wavelength l=7.97 nm it was pos sible to detect the fifth harmonic at 1.59 nm with an average energy of 3.5 nJ. This wave length corresponds to the Co L3 absorption edge and enabled us to perform the first resonant magnetic scattering experiment using FEL pulses of about 20 fs duration. Contact person, ESS seminars:
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Speaker: Gerhard Grübel, Deutsches Elektronen-Synchrotron (DESY).