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Ischia Island (Naples, Italy)30|04 - 03|05 2009Aragonese CastlePhoto courtesy of Giovanni Mattera [www.giannimattera.it]BookofAbstractsORGANISING COMMITTEECarlo ALTUCCI (University of Naples, IT)Pietro Paolo CORSO (University of Palermo, IT)Rosario ESPOSITO (University of Naples, IT)Jonathan MARANGOS (Imperial College, UK)John TISCH (Imperial College, UK)Raffaele VELOTTA (University of Naples, IT)Università degli Studidi Napoli Federico IIImperial Collegehttp://ultrafast09.fisica.unina.it

UDIM09Second International Conference onUltra-fast Dynamic Imaging of MatterHotel Continental Terme, Ischia (Italy)30 th April – 3 rd May 2009

The organisers wish to thank the European Science Foundation who has strongly supportedUDIM09 through the activity DYNA (Ultrafast Structural Dynamics in Physics, Chemistry,Biology and Material Science).The European Science Foundation (ESF) was established in 1974 to create a common Europeanplatform for cross-border cooperation in all aspects of scientific research.With its emphasis on a multidisciplinary and pan-European approach, the Foundation providesthe leadership necessary to open new frontiers in European science.Its activities include providing science policy advice (Science Strategy); stimulating cooperationbetween researchers and organisations to explore new directions (Science Synergy);and the administration of externally funded programmes (Science Management). These takeplace in the following areas: Physical and engineering sciences; Medical sciences; Life, earthand environmental sciences; Humanities; Social sciences; Polar; Marine; Space; Radioastronomy frequencies; Nuclear physics.Headquartered in Strasbourg with offices in Brussels, the ESF’s membership comprises 75national funding agencies, research performing agencies and academies from 30 Europeannations.The Foundation’s independence allows the ESF to objectively represent the priorities of allthese members.

Journal ofModern OpticsCALL FOR PAPERSSpecial IssueUltra-Fast Dynamic ImagingGuest EditorsRaffaele Velotta — Università di Napoli, rvelotta@unina.itCarlo Altucci — Università di Napoli, caltucci@unina.itJournal of Modern OpticsEditorial BoardEditor:Jon Marangos — Imperial College London, UKAssociate Editor:William L. Barnes — University of Exeter, UKEditorial Board:G. S. Agarwal — Oklahoma State University, OK, USAS. M. Barnett FRS FRSE — University of Strathclyde, Glasgow,UKA. Beige — University of Leeds, UKK. Blow — Aston University, Birmingham, UKK. Burnett CBE FRS - University of Oxford, UKV. Buzek — Slovak Academy of Sciences, Bratislava, SlovakiaK. W. Cheah — Hong Kong Baptist University, Hong KongS. Enoch — Institut Fresnel, Marseille, FranceW. J. Firth FRSE — University of Strathclyde, Glasgow, UKA. Harvey — Heriot Watt University, Edinburgh, UKM. Ivanov — Steacie Institute for Molecular Sciences, CanadaP. L. Knight, KB, FRS — Imperial College London, UKV. Lakshminarayanan — University of Waterloo, Ontario, CanadaM. Padgett FRSE — University of Glasgow, UKF. Persico — University of Palermo, ItalyM. G. Raymer — University of Oregon, OR, USAI. Walmsley — University of Oxford, UKG. R.Welch — Texas A&M University, TX, USAE. Wolf — University of Rochester, NY, USAF. Wyrowski — University of Jena, Germanywww.tandf.co.uk/journals/jmoThe Guest Editors invite you tosubmit your papers for this specialissue of the Journal of Modern OpticsThis special issue aims to bring together contributionsto ultrafast molecular imaging from researchersworking both with large scale facilities (synchrotronand free electron lasers) and with table top ultrashortsource. The following topics will be covered:••••••••AttoscienceHHG molecular imagingFEL and synchrotron researchNovel ultrafast spectroscopic techniquesUltrafast electron diffractionWavepacket motion and coherent control ofreactionsKinetics of laser induced ChemistryUltrafast processes in BiologyDeadline for submissions: 31st July 2009Submission GuidelinesAll papers for consideration should besubmitted online at the Journal of ModernOptics Manuscript Central site at: http://mc.manuscriptcentral.com/tmop. Please includeon the title page that the paper is intended forthe special issue “Ultra-Fast Dynamic Imaging”.More information is available at the Journalhomepage at www.tandf.co.uk/journals/jmounder the “Instructions for Authors” tab.Taylor & Francis | 4 Park Square | Milton Park | Abingdon | OX14 4RN | UK

Table of contentIntroduction 1Committees 2Conference program 3Abstracts 7List of participants 72

IntroductionUltra-Fast Dynamic Imaging of Matter has the aim to gather together researchers working withaccelerator based light sources and ultrashort lasers. These two communities are experiencing a fastprogress in their fields with their interests converging towards the availability of femtosecond andsub-femtosecond light pulses which will make feasible the observation of physical and chemicalprocess in real time.Since the first meeting held in London, 9 th -11 th April 2006 there has been significant progresstowards the goal of real time imaging of physical and chemical processes using both acceleratorbased sources (synchrotron sources, fourth generation light sources) and lasers. X-ray free-electronlasers are now being proposed in several countries and these new machines are potentially capableof sub-10fs x-ray diffraction imaging on single bio-molecules. In parallel new laser basedtechniques, made possible by the advent of few-cycle amplified optical pulses, have recently beenadvanced that enable the access to sub-femtosecond (attosecond domain) imaging. These includetechniques based on attosecond XUV pulses generated by high order harmonic generation inmolecules and the direct probing of molecules using their own electrons driven under the influenceof intense fields. It is therefore very timely to review in this second meeting on Ultra-Fast DynamicImaging of Matter the wide ranging advances that have been taking place across several differentfields in physics and chemistry. As it was the case for the first edition, the conference will attractboth the specialist practitioners of the techniques and the potential beneficiaries of these ideas. Thisis a highly interdisciplinary topic with a broad interest to physicists, chemists, material scientistsand life-scientists. The purpose of the meeting will therefore be to bring together leading membersfrom a number of diverse scientific communities that have been at the forefront in this area in recentyears. We hope that the cross-fertilisation between fields will promote further research especially inareas of common interest.1

CommitteesInternational Advisory CommitteeRafael Abela (Swiss Light Source, Paul Scherrer Institut, Villigen, CH).Massimo Altarelli (DESY, Hamburg, DE)Paul Corkum (NRC Steacie Institute, Ottawa, CA)Louis DiMauro (Ohio State University, US)Roger Falcone (University of California, Berkeley, US)Misha Ivanov (NRC Steacie Institute, Ottawa, CA)Mauro Nisoli (Politecnico di Milano, IT)Marc Vrakking (Amolf FOM, Amsterdam, NL)Kiyoshi Ueda (Tohoku University, JP)Organising CommitteeCarlo Altucci (University of Naples, IT)Pietro Paolo Corso (University of Palermo, IT)Rosario Esposito (University of Naples, IT)Jonathan Marangos (Imperial College, UK)John Tisch (Imperial College, UK)Raffaele Velotta (University of Naples, IT)2

Conference ProgramWednesday 29 th April19:00 – 21:00 Ischia, Hotel Continental Terme, Registration & Welcome cocktailThursday 30 th April08:50 Opening RemarksMorning session: Attosecond Electron Dynamics I (Chair: R. Velotta)9.00 – 9.30 P. Abbamonte, Imaging attosecond electron dynamics in graphite and graphenewith inelastic X-ray scattering.9.30 – 10.00 R. Dörner, Interference and electron entanglement in photo-ionization of H 2 and N 2 .10.00 – 10.30 R. Kienberger, Attosecond physics.10.30 – 11.00 Coffee break.11.00 – 11.30 G. Sansone, Attosecond dynamics of electron wavepackets in atoms and molecules.11.30 – 12.00 O. Smirnova, Time and space resolved high harmonic imaging of electrontunnelling from molecules.12.30 - 13.30 LunchAfternoon session: Ultrafast Dynamics of Molecules I (Chair: A. L’Huillier)14.00 – 14.30 P. Corkum, A laser STM for molecules.14.30 – 15.00 H. Sakai, Controlling the molecular orientation in the laser-field-free condition.15.00 – 15.30 S. Baker, Probing molecular structure and dynamics using laser driven electronrecollisions.15.30 – 16.00 M. Lein, The phase in molecular high-harmonic generation.16.00 – 16.30 Coffee break.16.30 – 17.00 C. D. Lin, Quantitative rescattering theory of dynamic chemical imaging withinfrared lasers.3

17.00 – 17.15 C. Vozzi, High order harmonics driven by IR parametric source.17.15 – 17.30 C. Figueira de Morisson Faria, Nonsequential double ionization in diatomicmolecules: one and two-centre rescattering17.30 – 17.45 M. Meckel, Laser-induced electron tunnelling and diffraction.17.45 – 18.00 R. de Nalda, Imaging real time bond breaking in molecules and clusters18.00 – 18.15 F. Lépine, Imaging electron dynamics in C 60 from femto- to microsecond timescale.18.15 – 18.30 E. Fiordilino, High-order harmonic generation from molecules: classical versusquantum effects.Friday 1 st MayMorning session: Ultrafast Dynamics of Molecules II (Chair: C. D. Lin)9.00 – 9.30 P. Salières, Experimental tomographic reconstruction of molecular orbitals usingHHG.9.30 – 10.00 H. Stapelfeldt, Quantum state selection of polar molecules: Alignment, orientationand conformational control.10.00 – 10.30 D. Villeneuve, Following molecular dynamics using high harmonic generation.10.30 – 11.00 Coffee break11.00 – 11.30 K. Ueda, Momentum imaging for ultrafast molecular imaging: from synchrotronradiation to femtosecond laser to XFEL.11.30 – 11.45 C. Pellegrini, X-ray Free-electron Lasers.11.45 – 12.00 J. Marangos, UK New Light Source (NLS).12.30 - 13.30 Lunch13.30 – 15.00 Poster sessionAfternoon session: Attosecond Electron Dynamics II (Chair: P. Corkum)15.00 – 15.30 J. Ullrich, Attosecond steering of electronic motion in atoms and molecules via ~6 fsCE phase stabilized pulses.15.30 – 16.00 K. L. Ishikawa, Wavelength dependence of high-harmonic generation.16.00 – 16.30 A. L’Huillier, Generation and application of attosecond pulse trains.4

16.30 – 16.45 V. Tosa, Macroscopic effects in single attosecond pulse generation.16.45 – 17.15 Coffee break.Afternoon session: Structural Dynamics of Complex Systems I (Chair: M. Chergui)17.15 – 17.45 S. Glenzer, Ultra-fast probing of shock-compressed matter with X-ray Thomsonscattering.17.45 – 18.00 D. Boschetto, Ultrafast dynamics and phase transition in photoexcited bismuthcrystal.18.00 – 18.15 P. Wochner, X-ray cross correlation analysis uncovers hidden local symmetries indisordered matter.18.15 – 18.30 B. Mansart, Ultrafast dynamical response of the prototype Mott compound V 2 O 3 .Saturday 2 nd MayMorning session: Structural Dynamics of Complex Systems II (Chair: S. Glenzer)9.00 – 9.30 J. Stohr, Ultrafast manipulation of the magnetization.9.30 – 10.00 H. Dürr, Ultrafast electron and spin dynamics in ferromagnets.10.00 – 10.30 J. Rost, Ultrafast electronic processes in clusters.10.30 – 11.00 M. Aeschlimann, Time-resolved photoemission electron microscopy -Nanoscale spectroscopy with femtosecond resolution11.00 – 11.30 Coffee break.11.30 – 12.00 M. Chergui, Optical and X-ray studies of the ultrafast dynamics of molecularsystems in liquids.12.00 – 12.30 D. Miller, “Making the Molecular Movie”: Quest for the structure-functioncorrelation of biology.12.30 – 13.00 I. P. Mercer, Quantum dimension of photosynthesis revealed by powerful new lasertechnique.13.00 – 14.30 Lunch16.00 Boat trip around the island20.00 Social diner5

Sunday 3 rd MayMorning session: New Methods and Sources (Chair: J. Rossbach)9.00 – 9.30 K. Midorikawa, Water window X-ray generation by phase-matched high harmonicswith neutral media.9.30 – 10.00 S. Boutet, Linac coherent light source and single molecule imaging.10.00 – 10.30 J. Costello, Two colour and two photon ionization processes in intense EUV andoptical fields at “FLASH”.10.30 – 11.00 Coffee break.11.00 – 11.30 T. Tschentscher, Investigation of ultrafast structural changes in complex chemicalsystems using X-ray FELs.11.30 – 12.30 Round table discussion (coordinator: J. Marangos): Future Challenges andProspects for Ultra-Fast Dynamics Imaging.12.30 – 13.30 Lunch.6

Abstracts7

Thursday 30 th April9:00 – 12:00Morning session:Attosecond Electron Dynamics IChair: R. Velotta8

IMAGING ATTOSECOND ELECTRON DYNAMICS IN GRAPHITE ANDGRAPHENE WITH INELASTIC X-RAY SCATTERINGJames P. Reed 1 , Young Il Joe 1 , Bruno Uchoa 1 , Diego Casa 2 , Thomas Gog 2 , Yong Cai 3 ,and Peter Abbamonte 11 Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana, IL, USA2 Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA3 NSLS II, Brookhaven National Laboratory, Upton, NY, USAX-ray scattering is a static imaging technique that has been widely applied to both periodicand non-periodic objects. The key technical challenge in x-ray imaging is to overcome the “phaseproblem”, i.e. to recover the missing phases that are lost because x-ray experiments measure anintensity, E 2 , rather than the electric field itself.In this talk I will describe a solution to the phase problem for inelastic x-ray scattering, thatallows dynamical imaging of charge propagation in a material 1,2 . The method is a four-stepprocedure involving i. symmetrization of the data, ii. analytic continuation, iii. a temporal sinetransform, and finally iv. a spatial Fourier transform. This technique yields the density propagator,χ( x, t) = −i / h 0 ˆ ρ( x, t), ˆ ρ(0,0) 0 θ ( t), which is a general measure of how charge propagates[ ]around a system.Our most recent use of this technique has been to image background screening processes ingraphite, with a time resolution of ∆t = 26 attoseconds and spatial resolution of ∆r = 0.53 Å. Thescreening is found to be extremely anisotropic, due to the existence of van Hove singularities near Land M points in Brillouin zone. From these results we can extract the individual screeningproperties of the graphene layers. We have determined, among other things, a backgrounddielectric constant of ε graphene ~14, which potentially explains the absence of a divergence in theFermi velocity near the Dirac points in graphene.1 P. Abbamonte, K. D. Finkelstein, M. D. Collins, and S. M. Gruner, Imaging density disturbances in water with a 41.3attosecond time resolution. Phys. Rev. Lett. 92, 237401 (2004).2 P. Abbamonte, et. al., Dynamical reconstruction of the exciton in LiF with inelastic x-ray scattering. Proc. Natl. Acad.Sci. 105, 12159 (2008).9

INTERFERENCE AND ELECTRON ENTANGLEMENT INPHOTOIONIZATION OF H 2 AND N 2M. Schöffler 1,2 , D. Akoury 1 , K. Kreidi 1 , T. Jahnke 1 , Th.Weber 2 , N. Neumann 1 , J. Titze 1 , L. Ph. H.Schmidt 1 , A. Czasch 1 , O. Jagutzki 1 , R.A. Costa Fraga 1 , R.E. Grisenti 1 , R. Diez Muino 3 , N.A.Cherepkov 4 , S.K. Semenov 4 , P. Ranitovic 5 , C.L. Cocke 5 , T. Osipov 2 , H. Adaniya 6 , J.C. Thompson 6 ,M.H. Prior 2 , A. Belkacem 2 , A. Landers 6 , H. Schmidt- Böcking 1R. Dörner 11 Institut ür Kernphysik, University Frankfurt,Max von Laue Str 1, D-60438 Frankfurt Germany2 Lawrence Berkeley National Lab., Berkeley CA 947203 Centro de Física de Materiales and Donostia InternationalPhysics Center, 20018 San Sebasian, Spain4 State University of Aerospace Instrumentation,190000 St. Petersburg, Russia5 Dept of Physics, Kansas State Univ, Cardwell Hall, Manhattan KS 66506\\5 Department of Physics, Auburn University Auburn AL 36849The talk will report on many particle coincident imaging experiments on direct double ionization ofH 2 and innershell ionization followed by Auger decay of N 2 . Both electrons and both ions aremeasured in coincidence.For H 2 we show Thomas Young type double slit interference and how it is lost by electron-.electron correlations. This simple 4 body systems shows the first onset of the transition from thequantum to the classical world 1,2 .For innershell ionization of N 2 we find a surprising solution for the 30 year old puzzle of core holelocalization. We use the Auger electron as a ultrafast probe for the localized or delocalizedcharacter of the innershell hole. We show that and how localization arises from quantumentanglement of the photo and Auger electron. Depending on photon energy and direction of thephotoelectron the Auger angular distribution shows broken or restored symmetry which directlyreflects the character of the innershell hole 3 .___________________________________1 Akoury et al. Science 318, 949 (2007)2 Kreidi at al. Phys.Rev.Lett. 100, 133005 (2008)3 Schöffler et al. Science 320, 920 (2008)10

ATTOSECOND PHYSICSR. KienbergerMax-Planck-Institut für Quantenoptik, Garching,Ludwig-Maximilians-Universität München, GermanyFundamental processes in atoms, molecules, as well as condensed matter are triggered or mediatedby the motion of electrons inside or between atoms. Electronic dynamics on atomic length scalestends to unfold within tens to thousands of attoseconds (1 attosecond [as] = 10 -18 s). Recentbreakthroughs in laser science are now opening the door to watching and controlling these hithertoinaccessible microscopic dynamics.The key to accessing the attosecond time domain is the control of the electric field of (visible) light,which varies its strength and direction within less than a femtosecond (1 femtosecond = 1000attoseconds). Atoms exposed to a few oscillations cycles of intense laser light are able to emit asingle extreme ultraviolet (xuv) burst lasting less than one femtosecond 1,2 . Full control of theevolution of the electromagnetic field in laser pulses comprising a few wave cycles 3 have recentlyallowed the reproducible generation and measurement of isolated sub-femtosecond xuv pulses 4 ,demonstrating the control of microscopic processes (electron motion and photon emission) on anattosecond time scale. These tools have enabled us to visualize the oscillating electric field ofvisible light with an attosecond “oscilloscope” 5 , to control and probe single- and multi-electrondynamics in atoms 6,7 , molecules 8 and solids 9 . Recent experiments indicate the feasibility ofextending to frontiers of attosecond metrology towards kiloelectronvolt photon energies 10 ,Megaelectronvolt electron energies 11 , and a temporal resolution approaching the atomic unit of time(~ 24 as) 12 .1 M. Hentschel et al., Nature 414, 509 (2001).2 R. Kienberger et al., Science 291, 1923 (2002).3 A. Baltuska et al., Nature 421, 611 (2003).4 R. Kienberger et al., Nature 427, 817 (2004).5 E. Goulielmakis et al., Science 305, 1267 (2004);6 M. Drescher et al., Nature 419, 803 (2002).7 M. Uiberacker et al., Nature 446, 627 (2007).8 M. Kling et al., Science 312, 246 (2006).9 A. Cavalieri et al., Nature 449, 1029 (2007).10 J. Seres et al, Nature 433, 596 (2005).11 L. Veisz et al., zur Veröffentlichung eingereicht (2008).12 E. Goulielmakis et al., Science 320, 1614 (2008).11

ATTOSECOND DYNAMICS OF ELECTRON WAVEPACKETSIN ATOMS AND MOLECULES.G. Sansone 1 , F. Kelkensberg 2 , M.F. Kling 3 , E. Benedetti 1 , F. Ferrari 1 ,W. Siu 2 , O. Ghafur 2 , P.Johnsson 2 , M. Swoboda 4 , T. Remetter 4 , F. Lépine 5 , S. Zherebtsov 3 , I. Znakovskaya 3 , M.Yu.Ivanov 6 , J.F. Pérez 7 , F. Morales 7 , J.L. Sanz-Vicario 8 , A. L'Huillier 4 , F. Martín 7 , M. Nisoli 2 andM.J.J. Vrakking 2 .1 National Laboratory for Ultrafast and Ultraintense Optical Science, Department of Physics,Politecnico of Milan, Piazza Leonardo da Vinci 32, 20133 Milano, Italy2 FOM-Institute AMOLF, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands3 Max-Planck Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, Garching, Germany4 Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden5 Universit Lyon 1;CNRS;LASIM, UMR 5579, Villeurbane, France6 National Research Council of Canada, 100 Sussex Drive, Ontario K1A 0R6 Ottawa, Canada7 Departamento de Química, Universidad Autonoma de Madrid, 28049 Madrid, Spain8 GFAM, Instituto de Física, Universidad de Antioquia, AA1226 Medellín, ColombiaSingle attosecond pulses (SAP) are opening new perspectives in the control of chemical reaction asthey allow to steer the motion of electronic wave packets on their natural timescale 1 . In thiscontribution we report experimental evidences for the control of electron localization on H 2 and D 2molecules. In the experiment, SAP, with a bandwidth extending between 20 and 40 eV, wereproduced by carrier-envelope phase stabilized few-cycle pulse with a time dependent ellipticity.The pulses were used to initiate an ultrafast dynamics in H 2 and D 2 . Several states of the neutralmolecule (autoionizing states) or of the molecular ion (1sσ g and 2pσ u ) can be accessed due to thelarge bandwidth of the SAP. The subsequent electron dynamics was probed and controlled using asynchronized infrared few-cycle pulse with an intensity of I=3x10 12 W/cm 2 .The energy E and angular distribution of the D + and H + ions was measured using a velocity mapimaging spectrometer as a function of the delay τ between the pump and probe pulses. Thesignature of the different excitation mechanisms can be identified in the energy distribution of theions. By changing the delay τ, the relative number of ions emitted in opposite direction can bevaried, indicating that electron dynamics can be steered by the probe beam during the moleculardissociation.1 F. Krausz and M. Ivanov Attosecond Physics Rev. Mod. Phys. 81, 163 (2009).12

TIME AND SPACE RESOLVED HIGH HARMONIC IMAGING OFELECTRON TUNNELING FROM MOLECULESOlga Smirnova 1,2 , Serguei Patchkovskii 2 , YannMairesse 2,4 , Nirit Dudovich 2,5 David Villeneuve 2 ,Paul Corkum 2 , and Misha Yu. Ivanov 2,31 Max-Born-Institute, Max-Born-Str. 2A, 12489 Berlin, Germany2 National Research Council, 100 Sussex Drive, Ottawa,Ontario K1A 0R6, Canada3 Imperial College of Science, Technology and Medicine, London SW7 2BW, United Kingdom4 CELIA, Universite Bordeaux I, UMR 5107 (CNRS, Bordeaux 1, CEA), 351 Cours de laLiberation, 33405 Talence Cedex, France5 Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100,IsraelHigh harmonic generation in intense laser fields carries the promise of combining sub-Angstromspatial and attosecond temporal resolution of electronic structures and dynamics in molecules, seee.g 1,2,3 . High harmonic emission occurs when an electron detached from a molecule by an intenselaser field recombines with the parent ion 4 . Similar to Young's double-slit experiment,recombination to several 'lobes' of thesame molecular orbital can produce interference minima and maxima in harmonic intensities 1 .These minima (maxima) carry structural information -- they occur when the de-Broglie wavelengthof the recombining electron matches distances between the centers. We demonstrate boththeoretically and experimentally that amplitude minima (maxima) in the harmonic spectra can alsohave dynamical origin, reflecting multi-electron dynamics in the molecule. We use high harmonicspectra to record this dynamics and reconstruct the position of the hole left in the molecule afterionization. Experimental data are consistent with the hole starting in different places as theionization dynamics changes from tunnelling to the multi-photon regime. Importantly, holelocalization and subsequent attosecond dynamics are induced even in the tunnelling limit. Thus,even 'static' tunnelling induced by a tip of a tunnelling microscope will generate similar attoseconddynamics in a sample. We anticipate that our approach will become standard in disentanglingspatial and temporal information from high harmonic spectra of molecules.1 M. Lein et al. Phys. Rev. Lett. 88, 183903 (2002).2 J. Itatani et al Nature 432 , 834 (2004).3 S. Baker et al Science 312 , 424 (2006).4 P.B. Corkum Phys. Rev. Lett. 71, 994 (1993).13

Thursday 30 th April14:00 – 18:45Afternoon session:Ultrafast Dynamics of Molecules IChair: A. L’Huillier14

A LASER STM FOR MOLECULESA. Staudte 1 , H. Akagi 2 , M Meckel 3 , L. Arissian 1,4 , C. Smeenk 1 ,F. Turner 1,5 , and P. B. Corkum 11 Joint Laboratory for Attosecond ScienceUniversity of Ottawa and National Research Council, Ottawa, ON. K1A 0R6 Canada;2 Japan Atomic Energy Agency,Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan;3 Johann Wolfgang Goethe Universität, Max-von-Laue Straße 1, Frankfurt, Germany;4 Department of Physics, Texas A and M University, College Station, Texas, USA;5 Department of Physics, University of Waterloo, Waterloo, ON, CanadaTunnelling, one of the most fundamental manifestations of quantum mechanics, is apowerful platform from which technologies can be launched. Tunnelling allows surfaces to beimaged atom by atom and is often present in strong field science. In both solids and gases electronsescape from the outer regions of the orbital to the continuum, i.e. to the vacuum for multiphotonionization of gas phase molecules and to the conduction band of the metal-tip in STM. In an STM,a sharp tip is scanned across a metal surface to trace out the band structure of the solid. By analogy,rotating the molecule will trace out the structure of the highest occupied molecular orbital.Using O 2 and N 2 as examples, we show that the momentum distribution of the electron thatemerges from the tunnel is a filtered projection of the orbital from which it tunnelled.There is mounting evidence to suggest that lower lying levels contribute significantly to thetotal tunnelling probability in strong field experiments. The evidence arises from the structure ofhigh harmonic spectrum, but the interpretation is debated. Using the “molecular STM”, we resolvethis debate. We study HCl since it offers a second unique opportunity to isolate the tunnellingcontribution of the highest occupied molecular orbital (HOMO) from the one below (HOMO-1).Tunnelling from HOMO-1 softens the bond and, in the laser field, leads to fragmentation of themolecular ion. Hence, the break-up of an HCl molecule after ionization is a direct signature fortunnelling from a lower lying orbital.Our results show the asymmetry in tunnelling from hetero-nuclear molecules and confirmthat tunnelling naturally induces electron wave packet dynamics in the residual ion. They imply thatattosecond hole dynamics 1 , created by tunnelling, will be ubiquitous -- in atoms, molecules andsolids 2 .1 O. Smirnova, S. Patchkovskii, Y. Mairesse, N. Dudovich, D. Villeneuve, P. Corkum, and M. Y. Ivanov, “Time andSpace Resolved High Harmonic Imaging of Electron Tunnelling from Molecules”, submitted to Nature.2 M. Gertsvolf, H. Jean-Ruel, P. P. Rajeev, D. D. Klug, D. M. Rayner, and P. B. Corkum, “Orientation-DependentMultiphoton Ionization in Wide Band Gap Crystals”, PRL 101, 243001 (2008).15

CONTROLLING THE MOLECULAR ORIENTATIONIN THE LASER-FIELD-FREE CONDITIONHirofumi SakaiDepartment of Physics, Graduate School of Science, The University of Tokyo,7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, JapanWe have already realized both one- and three-dimensional molecular orientation with thecombination of a weak electrostatic field and an intense, nonresonant laser field. 1,2,3 I will reportrecent progress in the control of molecular orientation.We propose an approach to achieve laser-field-free molecular orientation with the combination of aweak electrostatic field and an intense, nonresonant laser field with a rapid turn off. 4 It is found thatthe adiabatically created pendular state is effectively transferred to the rotational wave packet in thenonadiabatic regime after the rapid turn of the laser pulse and that the orientation achieved at thepeak of the laser pulse is revived at the rotational period of the molecule with the same degree oforientation. Based on this approach, we demonstrate laser-field-free orientation of OCS moleculeswith the combination of an electrostatic field of 800 V/cm and an intense, nonresonant rapidlyturned-off laser field, which can be shaped with the plasma shutter technique. 5 As was expectedfrom theoretical simulations, molecular orientation is adiabatically created in the rising part of thelaser pulse, and it is found to revive at around the rotational period of an OCS molecule with thesame degree of orientation as that at the peak of the laser pulse in the virtually laser-field-freecondition. We further propose a technique to achieve completely field-free molecular orientationwith an intense, nonresonant, two-colour laser field with a slow turn on and rapid turn off. 6 Thetechnique is based on the combined effects of anisotropic hyperpolarizability interaction as well asanisotropic polarizability interaction. 71 H. Sakai, S. Minemoto, H. Nanjo, H. Tanji, and T. Suzuki, Phys. Rev. Lett. 90, 083001 (2003).2 S. Minemoto, H. Nanjo, H. Tanji, T. Suzuki, and H. Sakai, J. Chem. Phys. 118, 4052 (2003).3 H. Tanji, S. Minemoto, and H. Sakai, Phys. Rev. A 72, 063401 (2005).4 Y. Sugawara, A. Goban, S. Minemoto, and H. Sakai, Phys. Rev. A 77, 031403(R) (2008).5 A. Goban, S. Minemoto, and H. Sakai, Phys. Rev. Lett. 101, 013001 (2008).6 M. Muramatsu, M. Hita, S. Minemoto, and H. Sakai, Phys. Rev. A 79, 011403(R) (2009).7 T. Kanai and H. Sakai, J. Chem. Phys. 115, 5492 (2001).16

PROBING MOLECULAR STRUCTURE AND DYNAMICS USING LASERDRIVEN ELECTRON RECOLLISIONSS. Baker 1 , T. Siegel 1 , L. Brugnera 1 , R. Torres 1 , L. E. Chipperfield 1 , I. Procino 2 ,J. G. Underwood 2 , J. W. G. Tisch 1 , and J. P. Marangos 11 Quantum Optics and Laser Science, Department of Physics, Imperial College London, UK.2 Department of Physics and Astronomy, University College London, UK.The sub-cycle nature of high-harmonic generation (HHG) is of great interest due its potential toreveal correspondingly fast molecular dynamics. HHG has also been very successfully used as aprobe of molecular structure. It now seems possible that the nature of the electron collision mayalso be manipulated to enable more complete structural information to be obtained. Our group hasrecently conducted a number of experiments working towards the use of HHG to elucidatemolecular structure and attosecond dynamics.The PACER (probing attosecond dynamics by chirp-encoded recollision) technique, firstdemonstrated in 2006 1,2 , allowed the nuclear dynamics of H 2 , D 2 , CH 4 , and CD 4 followingionisation to be studied with a temporal resolution of 100as. More recently this technique has alsoallowed details of the electronic structure of the molecules used to be revealed 3 , through theobservation of a dynamic interference effect in the recombination event. We have also beenworking towards to goal of using HHG to image the electronic structure of larger, organicmolecules 4 . Recent results investigating HHG in a range of molecules using a driving field at 1300nm will be presented. The use of a longer wavelength driving field is beneficial as the recollidingelectron wavepacket contains higher energy components, and can thus probe the molecule withgreater spatial resolution.This work will be presented here and the potential of these techniques for further developmentdiscussed.1 S. Baker et al. Probing proton dynamics in molecules on an attosecond timescale, Science 312, 424 (2006).2 M. Lein. Attosecond probing of vibrational dynamics with high-harmonic generation, Phys. Rev. Lett. 94, 053004(2005).3 S. Baker et al. Dynamic two-centre interference in High-order harmonic generation from molecules with attosecondnuclear motion, Phys. Rev. Lett. 101, 053901 (2008).4 R. Torres et al. Probing orbital structure of polyatomic molecules by High-order harmonic generation, Phys. Rev.Lett. 98, 203007 (2007).17

THE PHASE IN MOLECULAR HIGH-HARMONIC GENERATIONM. Lein 1,2 , E. V. van der Zwan 2 , C.C.Chirilă 1,21 Institute for Theoretical Physics, Leibniz Universität Hannover, 30167 Hannover, Germany2 Institute of Physics, Universität Kassel, 34132 Kassel, GermanyIn high-harmonic generation from molecules, the shape of the active electronic orbital plays acrucial role in determining the emission spectra as well as the orientation dependence of theharmonics from aligned molecules. In simple molecules, minima in the harmonic emission can beapproximately understood as a signature of destructive interference. At such minima, the phaseundergoes a measurable phase jump 1 . The details of the phase jump are important for the shape ofthe produced attosecond pulses. It has been found theoretically and experimentally 2 that the jump isnot abrupt and the size of the jump differs from π. This cannot be explained in terms of a harmonicsignal passing exactly through zero. We investigate the phase jump using two different approaches:(i) the strong-field approximation for H 2 + using plane-wave matrix elements and (ii) numericalsolution of the time-dependent Schrödinger equation for 2D model systems. Both calculationssupport the conclusion that the width of the phase jump is due to a breakdown of the various saddlepointapproximations that are often adopted in the strong-field approximation. This effect istherefore related to the laser pulse parameters rather than to the molecular structure. Deviations ofthe continuum electron states from plane waves, on the other hand, appear to be relevant mainly forthe size of the phase jump. We discuss the implications for the Cooper minimum in the highharmonicemission spectrum from Argon atoms, where a phase jump appears as a consequence ofdestructive interference between different partial waves of the continuum electron.1 M. Lein et al., Role of the Intramolecular Phase in High-Harmonic Generation, Phys. Rev. Lett. 88, 183903 (2002).2 W. Boutu et al., Nature Phys. 4, 545 (2008).18

QUANTITATIVE RESCATTERING THEORY OF DYNAMIC CHEMICALIMAGING WITH INFRARED LASERSC. D. LinDepartment of Physics, Kansas State University, Manhattan, Kansas 66506, USABased on the rescattering concept, we have recently established 1-4 a quantitative rescattering theory(QRS) where HATI (or HHG) spectra are expressed as a product of the returning electron wavepacket with the elastic differential cross sections (DCS) between the target ion with free electrons(or photo-recombination cross section). The QRS has been established for atomic targets based onaccurate results obtained from solving the time-dependent Schrödinger equation (TDSE). It has alsobeen further established that the momentum distribution of the returning electron wave packet canbe obtained from the well-known Strong Field Approximation (SFA). According to the QRS, thestructure is contained in the DCS or PRCS, the laser information is contained in the wave packet,i.e., they are decoupled.The QRS has now been extended to calculate HHG spectra from aligned molecules to compare withexperiments. For atomic targets the QRS has been used to extract the DCS from the experimentalHATI spectra 5 , to predict and explain why the ATI spectra in the plateau region is flat or not 2 , andhow they depend on laser parameters. We have also shown that the electron wave packet extractedfrom the QRS can be used to retrieve laser parameters 5 , such as the peak intensity, pulse durationand carrier-envelope phase, and to obtain nonsequential double ionization yield of atoms 6 . The QRSallows calculations of HATI and HHG spectra with accuracy comparable to that from TDSE, butwith computer time comparable to that of the SFA. Thus laser focus volume effect on the HATIspectra and macroscopic propagation effect on the HHG spectra can also be investigatedtheoretically.1 T. Morishita et al. Accurate retrieval of structural information from laser-induced photoelectron and high- orderharmonic spectra by few-cycle laser pulse. Phys. Rev. Lett. 100, 013902 (2008).2Z. J. Chen et al. Origin of species dependence of high-energy plateau photoelectron spectra. J. Phys. B 42, 061001(2009).3A. T. Le et al. Extraction of the species-dependent dipole ampitude and phase from high-order harmonic spectra inrare gas atoms. Phys. Rev. A 78, 023814 (2008).4A. T. Le et al. Theory of high-order harmonic generation from molecules with intense laser pulses. J. Phys. B 41,081002 (2008).5S. Micheau et al. Accurate retrieval of target structure and laser parameters of few-cycle pulses from photoelectronmomentum spectra. Phys. Rev. Lett. 102, 073001 (2009).6S. Micheau et al. Quantitative rescattering theory for non-sequential double ionization of atoms by intense laserpulse. Phys. Rev. A 79, 013417 (2009).19

HIGH ORDER HARMONICS DRIVEN BY IR PARAMETRIC SOURCEC. Vozzi 1 , F. Calegari 1 , M. Nisoli 1 , G. Sansone 1 , S. De Silvestri 1 ,F. Frassetto 2 , L. Poletto 2 , P.Villoresi 2 , E. Balogh 3 , V. Tosa 3 , and S. Stagira 11 ULTRAS, CNR-INFM, Department of Physics, Politecnico di Milano, Italy2 LUXOR, CNR-INFM, Università di Padova, Italy3 Natl. Inst. RD Isotop & Mol. Technol, Cluj Napoca 400293, RomaniaWe investigated high-order harmonic generation (HHG) by carrier-envelope-phase stabilized fewcyclenear-IR parametric source in noble gases and simple molecules. This source is characterizedby 1500 nm central wavelength, almost transform limited pulse duration of about 20 fs and pulseenergy up to 1.2 mJ 1 . We observed a significant cutoff extension as compared to a standard 800 nmTi:Sapphire driving source for all these generating media.We studied the dependence of spectral features on phase-matching condition in harmonicsgenerated in argon and krypton. These features are well reproduced by HH calculation 2 , taking intoaccount macroscopic effects.We also investigated HHG driven by two color laser field, obtained by mixing our parametricsource with a small portion of the fundamental 800 nm laser field. Exploiting the tunability of theparametric amplification process, we were able to change the carrier wavelength of the parametricsource. When harmonics are generated by two electric field components at 1600 and 800 nm, weobserved even and odd harmonic due to the break in the generation process symmetry. We observeda broad continuum extending above 100 eV when the parametric source is tuned at a carrierwavelength of 1500 nm which is not exactly double with respect to the 800-nm laser source,thus demonstrating the approach of Merdji et al. 3 for isolated attosecond pulse generation andextending this approach to the spectral region above 100 eV.1 C. Vozzi et al. “Millijoule-level phase-stabilized few-optical-cycle infrared parametric source” Opt. Lett. 32, 2957(2007).2 V. Tosa et al. “High-order harmonic generation by chirped and self-guided femtosecond laser pulses. I. Spatial andspectral analysis” Phys. Rev. A 71, 063807 (2005).3 H. Merdji et al. “Isolated attosecond pulses using a detuned second-harmonic field” Opt. Lett. 32, 3134 (2007).20

NONSEQUENTIAL DOUBLE IONIZATION IN DIATOMIC MOLECULES:ONE AND TWO-CENTRE RESCATTERING 1Figueira de Morisson FariaDepartment of Physics and Astronomy, University College London,Gower Street, London WC1E 6BT, United KingdomWe investigate laser-induced nonsequential double ionization from aligned diatomic molecules,using the strong-field approximation (SFA) in its length and velocity gauge formulations. Weconsider that the first electron dislodges the second by electron-impact ionization. Employingmodified saddle-point equations, we single out the contributions of different scattering scenarios tothe maxima and minima observed in the differential electron momentum distributions. We showthat the quantum interference between the electron orbits starting and ending at a specific centre C jand those starting at C j and ending at a different centre C ν leads to the same maxima as minima as ifall possible scenarios are taken.There exist, however, quantitative differences as far as the gauge choice is concerned. Indeed, whilethe velocity-gauge distributions obtained employing only the above-mentioned processes arepractically identical to the overall distributions, their length-gauge counterparts exhibit anasymmetry in the positive and negative momentum regions. This asymmetry is due to additionalpotential-energy shifts, which are only present in the length-gauge formulation of the SFA.Depending on the centre, these shifts sink or increase the potential barrier through which the firstelectron tunnels. In contrast, the interference between topologically similar scenarios leads at mostto patterns whose positions, in momentum space, do not agree with the overall interferencecondition, neither in the length nor in the velocity gauge.It is rather interesting that, in the length gauge, the influence of the potential energy shifts can bedirectly mapped into the electron momentum distributions for the processes starting at the samecentre. In fact, different potential energy shifts lead to an enhancement or a suppression of thedistributions in distinct momentum regions. Hence, if these processes could be isolated in a realisticscenario, one could in principle determine from which side of the molecule the first electronreached the continuum. If no asymmetry is observed, the existence of the potential-energy shifts andthe validity of the length-gauge SFA electron momentum distributions could be ruled out fordiatomic molecules.1 C. Figueira de Morisson Faria, Laser-induced nonsequential double ionization in diatomic molecules: one and twocenterrescattering scenarios, arXiv: 0807.276321

LASER-INDUCED ELECTRON TNNELING AND DIFFRACTIONM. Meckel 1,2 , D. Comtois 3 , D. Zeidler 2,4 , A. Staudte 1,2 , D. Pavičić 2 , H. C. Bandulet 3 , H. Pépin 3 , J. C.Kieffer 3 , D. Dörner 1 , D. M. Villeneuve 2 , P. B. Corkum 21 Institut für Kernphysik, Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany2 Steacie Institute for Molecular Sciences, National Research Council, Ottawa, ON, Canada3 Institut National de la Recherche Scientifique – Énergie, Matériaux et Télécommunications,Varennes, QC, Canada4 Carl Zeiss SMT AG, Oberkochen, GermanyWe use a laser field to extract electrons from the molecule itself, accelerate them, and in some casesforce them to recollide with and diffract from the parent ion, all within a fraction of a laser period.The momentum distribution of the extracted electron carries the fingerprint of the highest occupiedmolecular orbital, whereas the elastically scattered electrons transmit the position of the nuclearcomponents of the molecule. 1We control the angular distributions of molecular axes at the instant of ionization by usingimpulsive molecular alignment 2 . The three-dimensional momentum vectors of emerging electronsand ions are recorded by a COLTRIMS reaction microscope 3 . A comparison of the electronmomentum distributions from aligned and anti-aligned molecules makes the above-mentionedeffects visible.Thus, in one comprehensive technology, the photoelectrons can give information about theelectronic orbital and the position of the nuclei.1 M. Meckel et al., Laser-Induced Electron Tunneling and Diffraction, Science 320, 1478 (2008).2 E.g.: P. W. Dooley at al., Direct imaging of rotational wave-packet dynamics of diatomic molecules, Phys. Rev. A 68,023406 (2003).3 E.g.: J. Ullrich et al., Recoil-ion and electron momentum spectroscopy: reaction-microscopes, Rep. Prog. Phys. 66,1463 (2003).22

IMAGING REAL TIME BOND BREAKING IN MOLECULES ANDCLUSTERSR. de Nalda 1 , J. Durá 2 , J. G. Izquierdo 3 , G. Amaral 3 , L. Bañares 31 Instituto de Química Física Rocasolano, CSIC, C/ Serrano 119, 28006 Madrid, Spain2 Unidad Asociada Departamento de Química Física I, Facultad de Ciencias Químicas, UniversidadComplutense de Madrid. 28040 Madrid, Spain and Instituto de Estructura de la Materia, CSIC, C/Serrano, 123. 28006 Madrid, Spain3 Departamento de Química Física I, Facultad de Ciencias Químicas, Universidad Complutense deMadrid, 28040 Madrid, SpainIn this contribution, we show direct measurements of dissociation times of molecular bonds inpolyatomic molecules and clusters. The bond chosen is C⎯I in the CH 3 I molecule (or the (CH 3 I) ncluster), which presents rich dynamics when excited to its A-band in the ultraviolet. The dynamicsinvolves non-adiabatic crossings between electronic surfaces, and different degrees ofvibrational/rotational excitation in the CH 3 fragment, with the result of a broad variety of channelsaccessed upon UV absorption. Those different channels are resolved by time-delayed ionization ofthe fragments and spatially resolved detection in velocity-map configuration (i.e. complete map ofvelocity vectors resulting from the bond breaking process). We will show a dual use of thistechnique: a) combined with resonant, ultrafast probing, it works as a stopwatch, and it has allowedus to follow the rupture of this benchmark molecular bond in unprecedented detail, since thereaction times found for the different channels are directly related with the non-adiabatic dynamicsof this multidimensional photodissociation reaction 1 ; b) combined with nonresonant, ultrafastprobing, it yields information on the transient species (and its potential surface) as it proceedstowards dissociation 2 . Additionally, we will show very recent results concerning the measurementof bond dissociation in (CH 3 I) 2 clusters. The study of the cluster introduces two types of novelties: asubtle one related to the bare molecule A-band being modified by the presence of a nearbymolecule, and novel dynamic channels related to new chemical rearrangements in the clusteredspecies. Evidence for both effects will be presented in this communication.________________________1 R. de Nalda, J. Durá, A. García-Vela, J. G. Izquierdo, J. González-Vázquez, and L. Bañares. J. Chem. Phys. 128,244309 (2008).2 J. Durá, R. de Nalda, J. Álvarez, J. G. Izquierdo, G. A. Amaral and L. Bañares. ChemPhysChem 9, 1245 (2008).23

IMAGING ELECTRON DYNAMICS IN C 60 FROM FS TO MICROSECONDTIMESCALE.Y. Huismans 1 , C. Cauchy 2 , E. Cormier 3 , P-A. Hervieux 4 , C. Bordas 2 , G. Gademann 1 , A.Gijsbertsen 1 , P. Logman 1 , F. Lépine 2 and M. Vrakking 1 ,1 AMOLF, FOM Amsterdam, The Netherlands2 LASIM, CNRS/Université Lyon 1, 69622 Villeurbanne, France3 CELIA, CEA Bordeaux, France4 IPCMS, CNRS/Université de Strasbourg, Strasbourg, Francelepine@lasim.univ-lyon1.frWe have used velocity map imaging spectrometry to study the influence of electronic andvibrational degrees of freedom on the ionization of photoexcited C 60 molecules. Thiscommunication presents experimental and theoretical results on the ionization processes of C 60occurring from femtosecond to microsecond timescale. The velocity distribution of the electronscarries direct information on the nature of the ionization process and therefore on the electrondynamics responsible for the ejection of the electron.When a short (30 fs) laser pulse ionizes C 60 , the electron spectrum is dominated by ATI peakswhich can be described by solving the Schrödinger equation. These measurements permit us to testthe single active electron picture in the case of molecular strong field ionization and to look formolecular effects. Moreover, angle resolved photoelectron measurements allow us to disentanglecoherent ionization (ATI) from fast statistical electronic emission (thermoelectronic). From thispoint of view velocity map imaging allows a clear distinction between coherent processes leading tohighly aligned electron emission, and statistical emission leading to isotropic emission. Aquantification of the loss of coherent can be obtained.When the laser pulse becomes much longer than the timescale of the vibronic couplings, themolecule can be considered as a reservoir of vibrationnal energy. The use of statistical theory isthen fully justified. In that case, time-resolved imaging demonstrates the purely thermionic natureof the process.Future experiments performed in the attosecond regime in order to access to the ultrafast electrondynamics will be discussed at the conference.24

HIGH-ORDER HARMONIC GENERATION FROM MOLECULES:CLASSICAL VERSUS QUANTUM EFFECTSE. Fiordilino, G. Castiglia, P.P. Corso, G. Orlando, F. PersicoDipartimento di Scienze Fisiche ed Astronomiche, Università degli Studi di Palermo, Via Archirafi36, 90123 Palermo and CNISMWe investigate High-Order Harmonic Generation from simple molecules and molecular ions; inparticular we are mainly interested on the effects of the nuclei dynamics on the emitted spectra.These effects are mainly related to both the appearance of satellite peaks around the usual oddharmonics and to an evident isotopic effect which allows to relate the intensity of the emitted linesto the mass of the isotopes. Furthermore we show that the presence of the satellite peaks isexplainable in terms of just a classical model of nuclei dynamics; on the contrary, the isotopic effectis only observable if we describe the nuclei as quantum objects. All the discussed results have beenobtained by numerically solving the time-dependent Schroedinger equations of the investigatedsystems.25

Friday 1 st May9:00 – 12:00Morning session:Ultrafast Dynamics of Molecules IIChair: C.D. Lin26

EXPERIMENTAL TOMOGRAPHIC RECONSTRUCTION OFMOLECULAR ORBITALS USING HHGS. Haessler 1 , W. Boutu 1 , P. Breger 1 , M. Stankiewicz 2 , L.J. Frasinski 2 , R. Taieb 3 , J. Caillat 3 , A.Maquet 3 , T. Ruchon 1 , B. Carré 1 and P. Salières 11 CEA-Saclay, Service des Photons, Atomes et Molécules, 91191 Gif sur Yvette, France2 J.J. Thomson Physical Laboratory, Univ. of Reading, Whiteknights, Reading RG6 6AF, UK3 UPMC Univ. Paris 06, UMR 7614, Laboratoire de Chimie Physique-Matière et Rayonnement, 11rue Pierre et Marie Curie, 75231 Paris Cedex 05, France.A strong laser field interacting with atoms or molecules drives ultrafast intra-atomic/molecularelectron wavepackets on a subfemtosecond timescale, resulting in the emission of attosecond burstsof XUV light. In linear molecules, the interaction of the laser-driven electron wavepacket with thecore may lead to quantum interferences during the recombination step, as first proposed by Lein 1 . InBoutu 2 , we have characterized the attosecond emission from transiently-aligned CO 2 molecules andwe demonstrated that these interferences can be finely controlled by turning the molecular axis withrespect to the laser polarization, i.e. changing the electron recollision angle. Our control of theinterference results in an attosecond pulse shaping, useful for future applications in ultrafastcoherent control of atomic and molecular processes. Moreover our measurements give direct accessto the transition dipole matrix elements between the continuum states and the molecular orbitalsinvolved in the emission process. When the HOMO orbital gives the dominant contribution, Itatani 3proposed a tomographic reconstruction of the orbital within a plane wave approximation for therecolliding electron. We have performed a fully experimental reconstruction of the N 2 HOMO,where the polarization-resolved harmonic emission was characterized in amplitude and phase. Thisreconstruction exhibits Angström spatial resolution, mainly limited by the accessible spectral range.It also reveals the Coulombic character of the continuum waves (Haessler 4 ).1 M. Lein et al. Role of the intramolecular phase in high-harmonic generation. Phys. Rev. Lett. 88, 183903 (2002).2 W. Boutu et al. Coherent control of attosecond emission from aligned molecules. Nature Physics 4, 545 (2008).3 J. Itatani et al. Tomographic imaging of molecular orbitals. Nature 432, 867 (2004).4 S. Haessler et al. In preparation.27

QUANTUM STATE SELECTION OF POLAR MOLECULES:ALIGNMENT, ORIENTATION AND CONFORMATIONAL CONTROLHenrik Stapelfeldt 1 ,1 Department of Chemistry, University of Aarhus, DenmarkBuilding on ideas that go back to Stern in the 1920s we use an inhomogeneous static electric field todeflect a cold beam of polar molecules. The deflection spatially disperses the rotational quantumstates of the molecules. We show that the molecules residing in the lowest-lying rotational statescan be selected and used as targets for further experiments 1 . In particular, the quantum-stateselectedmolecules enable unprecedented strong alignment, induced by a moderately intense laserpulse, as well as strong orientation induced by a mixed laser and static electric field. Here,alignment refers to confinement of one or more molecule-fixed axes along laboratory-fixed axes,and orientation refers to the molecular dipole moments pointing in a specific direction. Also, it isshown that the deflection enables separation of the different conformers of a single molecule. Theexample of 3-aminophenol will be discussed.We discuss new opportunities offered by the enhanced degree of orientational control, madepossibly by quantum state selection, including time resolved studies of torsion, and eventuallyenantiomeric conversion, of axially chiral molecules.The work presented is done in collaboration with Jochen Küpper and Gerard Meijer, Fritz HaberInstitute, Berlin and Lars Bojer Madsen, Dept. of Physics, University of Aarhus.1 L. Holmegaard, J. H. Nielsen, I. Nevo, H. Stapelfeldt, F. Filsinger, J. Küpper, and G. Meijer Laser-Induced Alignmentand Orientation of Quantum-State-Selected Large Molecules, Phys. Rev. Lett. 102. 023001 (2009).28

FOLLOWING MOLECULAR DYNAMICSUSING HIGH HARMONIC GENERATIONDavid Villeneuve, Julien Bertrand, Paul Corkum and Hans Jakob WörnerNational Research Council of Canada, Ottawa ON CanadaHigh harmonic generation from molecules is known to be sensitive to the electronic structure of themolecule. We show that we can follow a unimolecular reaction in systems such as Br 2 and NO 2 . Asingle-photon pump pulse promotes the molecule to an excited electronic state, leading todissociation. The delayed probe pulse ionizes the molecule and creates high harmonic emission.By first aligning the molecule, it is possible to make the measurements in the molecular frame.Using a homodyne technique, we can determine both the amplitude and phase of the recombinationdipole matrix elements of the products along the complete reaction coordinate.High harmonic generation has many similarities to photoelectron spectroscopy since both involve atransition between a bound state and the continuum. We will compare the two approaches. HHG isa highly parallel measurement in which the photon energy, phase and polarization containinformation in the molecular frame, but has the disadvantage that the measurement takes place in astrong laser field.29

MOMENTUM IMAGING FOR ULTRAFAST MOLECULAR IMAGING:FROM SYNCHROTRON RADIATION TOFEMTOSECOND LASER TO XFELKiyoshi UedaIMRAM, Tohoku University, Sendai 8577, JAPANUsing position sensitive detectors in the ion time of flight (TOF) spectrometry, hit position on thedetector allows one to determine the momentum particle by particle. In particular, the use of delayline detectors is a well-established method for multi-particle momentum imaging. This method hasbeen successfully applied to synchrotron radiation (SR) experiments to probe ultrafast deformationof the core excited Molecules. 1 A combination between ion momentum imaging and electronmomentum imaging, often called as reaction microscope, 2 has also been used for SR experimentsas a powerful tool for photoelectron diffraction measurements of free molecules, again as ultrafastprobing for the transient shape of the molecule. 3 These momentum imaging techniques are nowcommonly used also for femto-second laser experiments. Especially, one can probe electronic andmolecular structure of the target ion using rescattering electrons, 4 which may be called ultrafastlaser induced electron microscope (LIEM). In near future, X-ray free electron lasers (XFELs) willbe in operation for user experiments. These new light sources will provide us with newopportunities for ultrafast coherent X-ray imaging of a single large-scale molecule. The number ofdiffracted photons from a single molecule is, however, limited and additional information such asthe orientation of the molecule is indispensable for retrieving the three dimensional structure of themolecule. Recently, we have developed a dead-time free detection system for ion momentumimaging and successfully used it to investigate multiple ionization of rare-gas clusters irradiated byextreme-ultraviolet FEL pulses from the SCSS test accelerator, 5 demonstrating that momentum foreach of more than one hundred ions produced by a single shot of FEL can be determined. 6,7 Webelieve that retrieval of the structure information from a coherent X-ray imaging of a singlemolecule become feasible if the dead-time detection system is used for determining the orientationof the molecule.1 K Ueda and J.H.D. Eland, J. Phys. B: At. Mol. Opt. Phys. 38, S839 (2005).2 J. Ullrich et al., Rep. Prog. Phys. 66, 1463 (2003).3 X,-J. Liu et al., Phys. Rev. Lett. 101, 109901 (2008).4 M. Okunishi et al., Phys. Rev. Lett. 100, 143001 (2008); D. Ray et al., Phys. Rev. Lett. 100, 143002 (2008).5 T. Shintake et al., Nature Photon. 2, 555 (2008).6 H. Fukuzwa et al., Phys. Rev. A Rap. Com. (in press).7 H. Iwayama et al., J. Phys. B: At. Mol. Opt. Phys. (accepted).30

X-RAY FREE-ELECTRON LASERSClaudio PellegriniDepartment of Physics and Astronomy, UCLA, 405 Hilgard Avenue, Los Angeles, California 90077.We review the present status and properties of X-ray free-electron lasers in operation or underconstruction in the nanometer and sub-nanometer wavelength range, and the novel possibilities theyoffer for the study of atomic and molecular processes. We also discuss recent developments inrelativistic electron beam physics, that give us the possibility of designing a new generation of X-ray free-electron lasers that: a. are more compact; b. reduce the radiation pulse duration to onefemtosecond or below; c. extend the photon energy to the 50 keV region. These results are obtainedby reducing the electron bunch charge while at same time maximizing the beam brightness andreducing the bunch length to a value near or smaller than the free-electron laser cooperation length.In the last case the radiation pulse is fully coherent in the longitudinal and transverse space. Theincrease in beam brightness can also be used to reduce the beam energy needed for a given radiationwavelength, when, at the same time, the undulator period is reduced. The simultaneous decrease inbeam energy and undulator period lead to a more compact free-electron laser, while the high beambrightness reduces the gain length and increases the coherent radiation intensity.31

UK NEW LIGHT SOUCESJon MarangosBlackett Laboratory, Imperial College of London, London SW7 2BW, United KingdomI will present a status report for the UK New Light Source (NLS) Project, based on advancedconventional and free electron lasers, with unique and world leading capabilities. The key sciencedrivers have been identified for this facility are:IMAGING NANOSCALE STRUCTURES.Instantaneous images of nanoscale objects can be recorded at any desired instant allowing,for example, nanometer scale resolution of sub-cellular structures in living systems.CAPTURING FLUCTUATING AND RAPIDLY EVOLVING SYSTEMS.Rapid intrinsic evolution and fluctuations in the positions of the constituents within mattercan be characterized.STRUCTURAL DYNAMICS UNDERLYING PHYSICAL AND CHEMICAL CHANGES.The structural dynamics governing physical, chemical and biochemical processes can befollowed by using laser pump- X-ray probe techniques.ULTRA-FAST DYNAMICS IN MULTI-ELECTRON SYSTEMS.New approaches to measuring the multi-electron quantum dynamics, that are present in allcomplex matter, will become possible.To address this science the following baseline specification has emerged for the facility:• High brightness (up to 10 12 photons/pulse) pulsed coherent light source coverage from THzto ~1keV (with harmonics to ~5 keV)• ~1kHz repetition rate with even pulse spacing• Photon source capable of smooth tuning across most of the spectral range• Pulse durations down to ~20 fs• Two-colour capability for pump probe experiments with synchronistaion jitter better than10fs. For example, Colour 1: THz- IR (pump)/ Colour 2: 100 eV-5 keV (probe)• High degree of transverse coherence• High degree of temporal coherence up to 400 eV, extending to >1 keV as seeding sourcesimprove• Synchronised to short pulsed lasers32

Friday 1 st May13:30 – 15:00Poster session33

P1AMPLITUDE AND PHASE OF THE HIGH HARMONIC RADIATIONIN ALIGNED MOLECULESJ. B. Bertrand, H. J. Wörner, D. M. Villeneuve, P. B. CorkumJoint Laboratory for Attosecond Science,National Research Council of Canada and University of Ottawa,100 Sussex Drive, Ottawa, ON, Canada K1A 0R6We use field-free alignment to generate harmonics in the molecular frame. In the same experiment,we perform a parallel measurement of the harmonic yield intensity and the ionization probability asa function of molecular alignment. The latter allows us to deconvolve the contribution of theionization step in the high harmonic generation process, in the molecular frame. This is madepossible given the known degree of alignment achieved in the experiment 1 . Respectively, for N 2 andBr 2 molecules, we observe that the angular-dependent ionization probability reflects the σ g and π gcharacter of the highest occupied molecular orbital (HOMO). In a complimentary two-sourceinterferometry 2 experiment, we retrieve the phase of the harmonic radiation coming from alignedmolecules with respect to unaligned molecules. Particularly, a phase-shift around harmonic number17 is observed in Br 2 . By removing the measured contribution of the ionization step, we obtain acomplete map of the dipole amplitude and phase in the molecular frame. 11 D. Pavicic et al, Phys. Rev. Lett. 98, 243001 (2007).2C. Corsi et al, Phys. Rev. Lett. 97, 023901 (2006).34

P2SCALING OF HIGH HARMONIC GENERATION EFFICIENCYWITH WAVELENGTHAndrew D. Shiner 1 , Carlos Trallero-Herrero 1 , Nathaniel Kajumba 1 ,Heidi-C Bandulet 2 , Daniel Comtois 2 , François Légaré 2 , and Jean-Claude Kieffer 2 ,Paul B. Corkum 1 and David M. Villeneuve 11 National Research Council of Canada, Ottawa, Canada2 INRS- Energie, Materiaux et Telecommunications, Varennes, QC, CanadaHigh Harmonic Generation (HHG) is an efficient process for producing radiation at XUVwavelengths. Higher XUV photon energies can be reached through this process by increasing thedriving laser wavelength; however, this comes at the expense of harmonic yield. The scaling ofXUV yield with laser wavelength remains an active area of investigation both theoretically 1,2 andexperimentally 3 .We present measurements of the scaling of XUV yield on laser wavelength for wavelengths from800 nm to 1.8 um. We operate with a thin (0.5 mm), low-density gas sample so that phase matchingis not influenced by plasma or material dispersion. The observed quadratic increase in harmonicyield with increasing pressure confirms that our measurement is not influenced phase mismatch. Inall cases we maintain a constant focal volume as we change wavelength by imaging the output of aspatial filter into the gas jet. The harmonic yield is measured with an XUV spectrometer. An iondetector located below the jet simultaneously records the ionization current. The linear dependenceof the ionization current on jet backing pressure proves that this signal is proportional to the numberof ions produced in the sample. We determine the harmonic yield per emitter by dividing the HHGspectrum by the square of the ion current. This measurement allows us to extract the single atomresponse. The resulting scaling laws for Kr and Xe will be presented which are found to be in goodagreement with current theories 50 .1 J. Tate et al. Scaling of Wave-Packet Dynamics in an Intense Midinfrared Field. Phys. Rev. Lett., 98, 13901 (2007).2 K. Schiessl et al. Quantum Path Interference in the Wavelength Dependence of High-Harmonic Generation. Phys.Rev. Lett. 99, 253903 (2007).3 P. Colosimo et al. Scaling strong-field interactions towards the classical limit. Nature Phys, 4, 386-389 (2008).35

P3ATTOSECOND HOMODYNE INTERFEROMETRY OF A CHEMICALREACTIONH. J. Wörner, J. B. Bertrand, P. B. Corkum and D. M. VilleneuveJoint laboratory for attosecond science,National Research Council of Canada and University of Ottawa,100, Sussex Drive, Ottawa, ON, Canada K1A0R6High-harmonic generation in aligned molecules provides information about their electronicstructure and ionization continuum within a fraction of a laser cycle. We exploit the ultrahigh timeresolution to observe a chemical reaction of fixed-in-space molecules. The experiment proceeds inthree steps: non-adiabatic alignment, impulsive excitation and high harmonic generation. We usethe photodissociation of Br 2 in a proof-of-principle experiment. The transient interference of highharmonics generated by the ground and the excited states results in a high visibilty of thephotodissociation process on the femtosecond time scale. The variation of the observed signal withharmonic order provides dynamic information on the attosecond time scale. We develop ahomodyne technique that enables us to extract the harmonic amplitude and phase of the excitedstate undergoing dynamics. Molecular frame information on the evolution of the electronic structurealong the dissociation coordinate and the associated ionization continuum is thereby obtained. Theresults indicate that the coherence of the atomic fragments manifests itself for very largeinternuclear separations. These experiments pave the way towards dynamic orbital tomography - amovie of the orbitals undergoing a chemical reaction.36

P4THE DEVELOPMENT OF AN ULTRAFAST LABORATORY AT DCU:A PROGRESS REPORTT. J. Kelly, P. Hayden and J. T. Costello1 National Centre for Plasma Science and TechnologySchool of Physical SciencesDublin City UniversityGlasnevinDublin 9The field of ultrafast science has been revolutionised in recent years by the developmentsurge in femtosecond laser technology which now permits unprecedented control over keyparameters such as amplitude, polarisation, frequency, phase and carrier envelope phase 1,2 . Thegeneration of coherent EUV radiation via the process of high harmonic generation or HHG 3 hasalso developed rapidly in parallel over the last three decades and even attosecond pulses may beproduced 4 . Hence it is now possible to prepare and probe atoms, molecules and other smallquantum systems in variously intense and/or coherent multicolour fields stretching from the NIR tothe EUV.An ultrafast laboratory is nearing completion at DCU with a laser capable of producingpulses with widths as short as 30 fs in a wavelength range from 267 nm to 2 µm. A multiplicity ofelectron, ion and photon detection techniques will be employed in coherent time resolved EUV +optical laser ionization and fragmentation of atoms and molecules. A report of the progress to dateand planned experiments will be presented.________________________1 Cavalieri AL, Goulielmakis E, Horvath B, Intense 1.5-cycle near infrared laser waveforms and their use for thegeneration of ultra-broadband soft-x-ray harmonic continua New Journal of Physics, Vol: 9, 242(2007)2 Brixner T, Krampert G, Pfeifer T, Selle R, Gerber G, Wollenhaupt M, Graefe O, Horn C, Liese D, Baumert T,Quantum control by ultrafast polarization shaping, Physical Review Letters, Vol: 92, 20(2004)3 M Ferray et al, Multiple Harmonic Conversion of 1064 nm radiation in rare- gases J. Phys. B: At. Mol. Opt. Phys.21(1988)4 Corkum PB, Krausz F, Attosecond Science, Nature Physics, Vol: 3, 381(2007)37

P5PROBING THE MOLECULAR ROTO-VIBRATIONALDYNAMICS EXCITED IN OPTICAL FILAMENTATIONF. Calegari, C. Vozzi, S. De Silvestri, S. StagiraNational Laboratory for Ultrafast and Ultraintense Optical Science, CNR – INFM ,Dipartimento di Fisica, Politecnico di Milano, I-20133, Milano, ItalyOptical filamentation in molecular gases shows peculiar features with respect to analogousphenomena in atomic media, owing to the occurrence of rotational and vibrational molecularexcitation. Indeed spatio-temporal effects, ascribed to the rotational Raman response, have beenrecently demonstrated in the wake of an optical filament excited in N 2 1 . The study of vibrationaleffects in filamentation is, on the other hand, at an early stage 2 .In this work we investigate the roto-vibrational excitation of a molecular medium induced byfilamentation of an ultrashort laser pulse. A first pump pulse (10 fs) was focused in a gas cellgenerating a filament which induced the roto-vibrational excitation in the molecular sample. Asecond pulse (10 fs) was used to probe the effects occurring in the filament wake. The central partof the two beams was sent to a spectrometer, which was used to record the UV tail of the spectrumas a function of the pump-probe delay.A first set of experiments was performed in CO 2 . The acquired pump-probe trace shows a beatbetween two modes at 1285.4 cm -1 and 1388.15 cm -1 . This beat demonstrates the excitation of theso-called Fermi doublet. Moreover, the Fourier analysis reveals the presence of hot bands aroundthis two modes, which suggests that overtone excitation must also be considered in ourexperimental conditions. Similar experiments have been performed also in H 2 . The acquired signalpresents a complex evolution indicating the roto-vibrational excitation of the molecules. Theexcitation of the very fast stretching mode of H 2 (4152 cm -1 ) demonstrates that during opticalfilamentation the pump pulse becomes self-compressed down to a pulse duration which enablesISRS of this Raman active mode.1 F. Calegari et al. Rotational Raman effects in the wake of optical filamentation Phys. Rev. Lett. 100, 123006 (2008).2 F. Calegari et al. Molecular rotovibrational dynamics excited in optical filamentation, Opt. Lett. 33, 2922 (2008).38

P6FEMTOSECOND STUDIES OF THE PHOTODISSOCIATION OF CH 3 I VIATHE B-BANDG. Gitzinger 1 , M.E. Corrales 2 , J. Durá 3 , G.A. Amaral 2 , R. de Nalda 1 , L. Bañares 21 Instituto de Química Física Rocasolano, CSIC, C/ Serrano, 119. 28006 Madrid, Spain2 Departamento de Química Fisica I, Facultad de Ciencias Químicas, Universidad Complutense deMadrid. 28040 Madrid, Spain3 Unidad Asociada Departamento de Química Física I, Facultad de Ciencias Químicas,Universidad Complutense de Madrid. 28040 Madrid, Spain and Instituto de Estructura de laMateria, CSIC, C/ Serrano, 123. 28006 Madrid. SpainFemtosecond CH 3 I photodissociation experiments via the B-band were carried out by the velocitymap imaging (VMI) technique using one photon excitation (“pump” laser centered at 200 nm) andion detection of CH 3 fragments by resonance enhanced multiphoton ionization (REMPI) with atime-delayed “probe” laser beam in the wavelength range 325-334 nm. The initial excitation leavesthe parent CH 3 I molecule in an excited 6s[1] Rydberg state with one vibrational quantum in the ν 6mode (CH 3 “rocking”) 1 . It is well known that at this wavelength two photodissociation channels arepossible. After predissociation from the Rydberg state, both channels lead to the formation ofground state CH 3 , but one of them produces I in its ground state ( 2 P 3/2 ) while the second oneproduces I in the spin orbit excited state ( 2 P 1/2 ). Some controversy has arisen at these excitationwavelengths with some authors claiming that the photodissociation proceeds entirely via the secondchannel 2 , while others have also detected the first channel with a quantum yield of up to 0.32 3 .In this work, we have been able to detect the formation of vibrationless CH 3 (ν=0) fragments as wellas vibrationally excited CH 3 in the ν 1 (CH stretch) and ν 2 (umbrella) modes. In all cases thedissociation proceeds entirely via the CH 3 +I( 2 P 1/2 ) channel. Our technique is sensitive to the spatialdistribution of the fragments; thus we have measured the anisotropy parameter for all types of CH 3 ,which corresponds in all cases to a perpendicular transition with β ∼ -0.8. Finally, our time resolvedexperiments have shown that the formation of ground state CH 3 as well as vibrationally excited CH 3occurs within similar subpicosend timescales.1 A.P. Baronvaski and J.C. Owrutksy. Vibronic dependence of the B State lifetimes of CH 3 I and CD 3 I usingfemtosecond photoionization spectroscopy. J. Chem. Phys. 108, 3445 (1998).2 G.N.A Van Veen et al. Predissociation of specific vibrational states in CH 3 I upon excitation around 193.3 nm.Chem. Phys. 97, 179 (1985).3 A. Gilchrist et al. Methyl Iodide photodissociation at 193 nm: The I(P) quantum yield. J. Phys. Chem. A. 112,4531 (2008).39

P7ULTRAFAST TABLETOP EXAFS: THE WAY TOWARDS DIRECTOBSERVATION OF MOLECULAR STRUCTURAL CHANGESJens Uhlig, Niklas Gador, Wilfred Fullagar and Villy SundströmDepartment of Chemical Physics, Lund University, Box 124, 22100 Lund, SwedenJens.Uhlig@chemphys.lu.sePhotochemistry and dynamics of molecules in nature and artificial systems is of enormouscontemporary interest. A small selection of applications includes solar cells, artificialphotosynthesis, photosensors, photostimulated chemistry and organic light emitting diodes (OLED).Direct real-time observation of molecular structural changes in these systems is highly desirable.Massive efforts are underway at large scale accelerator and laser facilities to generate and detectsuitably short bursts of X-rays for this purpose. This poster presents a novel table-top arrangementfor subpicosecond time resolved X-ray absorption measurements in a conventional laser laboratory.Our laser plasma X-ray generator produces isotropic bremsstrahlung bursts with detectable energiesin the range 3 – 15 keV from a simply constructed water jet target. Measurements suggest an X-raypulse duration of 400 fs or shorter. The spectrum is free from detectable emission lines, importantfor temporal and detection reasons.Moderate power ultrafast kHz repetition lasers in modern laboratories yield enough X-ray flux toenable resolution of local molecular structures within practical timeframes using the EXAFStechnique, when coupled to suitable detection systems. A helium or rough vacuum environmentallows a variety of liquid or solid samples without the constraints of high vacuum systems.We suggested and are poised to pioneer the use of a novel single photon mode micro calorimeterdetector array with sufficient energy resolution to allow EXAFS measurements directly. Thisdevelopment arises from extensive work with direct detection CCDs, bent crystal (focusing vonHamos) spectrometers, synchrotron EXAFS experiments and laser/X-ray characterisations. Themicro calorimeters offer energy resolution of ~4eV @ 6keV in a compact setup that does notmotivate higher fluxes than are already observed. The development is expected to enable EXAFSin widespread laser laboratories, with particular applications in the context of ultrafast structuraldynamics.40

P8VELOCITY MAP IMAGING OF HIGH ENERGY ELECTRONSD. C. Darios 1 , I. Procino 2 , M. Siano 1 , S. Baker 1 , R. Torres 1 , J.G. Underwood 2 and J. P. Marangos 11 Blackett Laboratory, Imperial College of London, London SW7 2BW, United Kingdom2 Department of Physics and Astronomy, University College London, London WC1E 6BT, UKVelocity Map Imaging (VMI) is a powerful experimental technique that allows directmeasurement of a two-dimensional (2D) projection of the velocity distribution of a photofragment.The VMI technique 1 is widely used because of its ease of use and excellent collection efficiency.We have developed a VMI spectrometer to study (high energy, up to 600 eV) electron rescatteringprocesses that occur when an atom/molecule is subjected to a strong laser field. The sameinstrument can also characterize the degree of laser induced alignment by observing the momentumdistribution of Coulomb exploded fragments.Our VMI spectrometer is equipped with three high voltage (up to 15 kV) electrostatic lensesthat direct the electrons/ions trajectories into a 15 cm long field-free time of flight tube towards amicrochannel plate detector followed by a phosphor screen. We use a commercial Titanium-Sapphire chirp-pulsed amplified (CPA) laser system operating at 1 kHz and producing pulses withenergy of 2.5 mJ and durations of ~45±5 fs. Intense and ultrashort laser pulses with duration of12.5±0.5 fs and energy up to 500 µJ are generated in a hollow-fibre pulse compression system thatis implemented at the output of our laser system.The pump beam aligns the molecules and then the intense and short probe pulse causesCoulomb explosion of the molecules. A pump-probe experiment in ion VMI configuration is firstused to characterize the degree of alignment in the molecules. The ion image contains informationon both the angular distribution and the kinetic energy of the fragments through the radialdistribution. We are also implementing the experimental observation of high energy electronsrescattering in atoms and/or diatomic molecules. If the momentum distribution of the rescatteredelectrons resulting from ionisation by the 12.5 fs pulse can be resolved with the VMI spectrometer,information of the molecular structure is gained without the need for numerical reconstruction.Finally, VMI spectrometers are easier to implement compared to COLTRIMS 2 apparatus andprovide high quality data.1 A. T. J. B. Eppink et al., Velocity map imaging of ions and electrons using electrostatic lenses: Application inphotoelectron and photofragment ion imaging of molecular oxygen, Review of scientific Instruments 68, 3477-3484(1997)2 M. Meckel, Laser-Induced Electron Tunneling and Diffraction, Science 320, 1478-1482 (2008)41

P9DEVELOPMENT OF AN ALGORITHM TO RETRIEVE 3DDISTRIBUTIONS IN A NON-CYLINDICAL SYMMETRIC VELOCITY MAPIMAGING SYSTEMI. Procino 1 , D. Darios 2 , S. Baker 2 , J. Underwood 1 , J. Marangos 21 Department of Physics and Astronomy, University College London, London WC1E 6BT, UK2 Blackett Laboratory, Imperial College London, London SW7 2BW, UKMeasurements on gas phase molecules performed on an isotropic sample suffer an averaging overall molecular orientations resulting in a loss of information. To gain information about themolecules it is necessary to define the molecular orientation at the point of making a measurement.This can be achieved by using a strong non-resonant linearly polarized laser field 1 . The molecularaxis alignment distribution induced from such a laser pulse can be measured by using CoulombExplosion Imaging technique 2 .We are developing an experiment for creating molecular axis alignment, and measuring it usingtime-resolved femtosecond laser Coulomb explosion in conjunction with velocity map imaging(VMI). Two laser beams are thus necessary: a linearly polarized pump laser beam aligns themolecules, and a circularly polarized laser beam Coulomb explodes them. We have chosen acircular polarization of the probe laser beam in order to obtain a uniform efficiency of the detectionfunction for each possible direction of the molecular axis in the polarization plane. However, such apolarization breaks the cylindrical symmetry of the exploded ions cloud. As a consequence an Abelinversion algorithm (a necessary step to obtain 3D distribution from 2D projection recorded withVMI) cannot be used to invert the acquired images.We present the development of a new algorithm that inverts the images obtained in ourexperimental configuration allowing the reconstruction of the angular and energy distributions ofthe ions. The angular distribution of the ions permits recovery of the degree of alignment of themolecules before the explosion.1 J. B. Fredrich and D. Herschbach, Alignment and Trapping of Molecules in Intense Laser Fields, Phys. Rev. Lett. 74,4623 (1995).2 J. J. Larsen et al., Three Dimensional Alignment of Molecules Using Elliptically Polarized Laser Fields, Phys. Rev.Lett. 85, 2470 (2000).42

P10A BRIEF SUMMARY OF EXPERIMENTS AT FLASH – IONISATION ININTENSE LASER FIELDSV Richardson 1 J. Dardis 1 , P. Hayden 1 , P. Hough 1 , E. T. Kennedy 1 , J. T. Costello 1 , S. Düsterer 2 , W.Li 2 , A. Azima 2 , H. Redlin 2 , K. Tiedke 2 , P. Juranic 2 , J. Feldhaus 2 , D. Cubaynes 3 , D. Glijer 3 , M.Meyer 3 , A.A. Sorokin 4 , M. Richter 4 , H. van der Hart 5 , N. Grum-Grzhimailo 6 E.V. Gryzlova 6 and S.I. Strakhova 6 , R. Taïeb 7 and A. Maquet 7 .1 School of Physical Sciences, National Centre for Plasma Science and Technology,Dublin City University, Dublin 9, Ireland, 2 HASYLAB, DESY, Notkestr. 85, D-22607 Hamburg,Germany, 3 LIXAM/ CNRS, UMR 8624 Centre Universitaire Paris-Sud, Bâtiment 350, F-91405Orsay Cedex, France, 4 Physikalisch-Technische Bundesanstalt, Abbestrasse 2-12, D-10587 Berlin,Germany, 5 Dept. Of Applied Mathematics and Theoretical Physics, David Bates Building, Queen’sUniversity Belfast, Belfast, BT7 1NN, Northern Ireland, 6 Institute of Nuclear Physics, MoscowState University, Moscow 119991, Russia, 7 UPMC, Université Paris 06, CNRS, UMR 7614,LCPMR, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05, FranceFLASH (Free electron LASer in Hamburg) operates on the principle of Self Amplified SpontaneousEmission (SASE) and produces coherent, bright and ultrashort eXtreme- UV (XUV) pulses 1 . Bysynchronizing FLASH with an independent optical laser, it is possible to induce and controlcoherent processes in superimposed, intense XUV and NIR fields. One such process isphotoelectron sideband generation 2 . In this class of experiment, photoelectrons are ejected by XUVradiation and simultaneously subjected to the intense field of an optical laser with which they canexchange photons. In effect, they absorb/emit photons with energy corresponding to ħω i.e. thatenergy of the optical laser photons 3,4 . As a consequence the photoelectron spectrum is no longercomprised of a single feature corresponding to the main photoline but is straddled by additionalphotoelectron lines separated by ħω - these are referred to as sidebands.The use of a highly developed EUVL Si-Mo multilayer mirror allows one to focus the FEL beam,resulting in ultrahigh intensities on the order of 10 -16 Wcm -2 5 . This intensity, coupled with a lowFEL wavelength (13nm) makes it possible to induce non-linear inner shell ionisation processes. Forthe first time using photoelectron spectroscopy, a signal has been detected resulting from the directtwo photon inner shell ionisation of an atom, in this case of the 4d subshell of xenon._______________________1 W. Ackermann et al, Nature Photonics 1 336 (2007).2 T.E. Glover et al., Phys Rev Lett. 76, 2468 (1996).3 P. Radcliffe et al, App Phys Lett, 90, 121109 (2007),.4 M. Meyer et al, Phys. Rev. Lett, 101 193002 (2008).5 A.A. Sorokin et al, Phys Rev Lett, 99, 213002 (2007).43

P11TIME-RESOLVED STIMULATED EMISSION SPECTROSCOPY IN THESUBPICOSECOND DOMAIN THROUGH PUMP–PROBE EXPERIMENTSS. Orlando 1 , A. Paladini 1 , L. Guidoni 2 , A. Santagata 1 , G.P. Parisi 1 , P. Villani 1,3 ,R. Teghil 3 , A. Galasso 3 , A. Giardini 11 CNR, Istituto di Metodologie Inorganiche e dei Plasmi, Sede di Potenza, I-85050, Tito Scalo (PZ),Italy2 CNRS, Materiaux et Phenomenes Quantiques UMR 7162, Universite Denis Diderot, Paris 7,Paris, France3 Dipartimento di Chimica, Universita` degli Studi della Basilicata, I-85100 Potenza, ItalyThe photoemission properties of fluorescent chromophores have a widespread application in manyfields ranging from chemical-physics and biology to organic light emitting devices. These systemsusually display high fluorescence conversion efficiency, which makes them suitable fortransient/gain experiments also in liquid solutions, thin films and eventually in proteinenvironments.Pump and probe methods have been widely employed for wavelength-resolved spectroscopy in thesubpicosecond time scale. In our group, we have recently assembled a new experimental setup forpump and probe spectroscopy: preliminary tests on the Rhodamine B dye in ethanol have beenperformed in order to optimize the setup. The dynamic response of photoinduced changes of thechromophore dispersed into a suitable solvent has been studied with a subpicosecond timeresolution.The optically prepared initial state of the Rhodamine B in ethanol solution appears to evolve on atimescale of few picoseconds into a successive state, which could be attributed to an intramolecularcharge transfer state.44

P12HIGH-ORDER HARMONIC GENERATION FROM MOLECULES:CLASSICAL VERSUS QUANTUM EFFECTSE. Fiordilino, G. Castiglia, P.P. Corso, G. Orlando, F. PersicoDipartimento di Scienze Fisiche ed Astronomiche, Università degli Studi di Palermo, Via Archirafi36, 90123 Palermo and CNISMWe investigate High-Order Harmonic Generation from simple molecules and molecular ions; inparticular we are mainly interested on the effects of the nuclei dynamics on the emitted spectra.These effects are mainly related to both the appearance of satellite peaks around the usual oddharmonics and to an evident isotopic effect which allows to relate the intensity of the emitted linesto the mass of the isotopes. Furthermore we show that the presence of the satellite peaks isexplainable in terms of just a classical model of nuclei dynamics; on the contrary, the isotopic effectis only observable if we describe the nuclei as quantum objects. All the discussed results have beenobtained by numerically solving the time-dependent Schroedinger equations of the investigatedsystems.45

P13CONCEPTUAL IDEAS FOR THE TEMPORAL OVERLAP OF THEELECTRON BEAM AND THE SEED LASER FOR SFLASHJ.Bödewadt 1 , J. Rossbach 1 , R.Tarkeshian* ,1 , V. Milchev 1H. Schlarb 2 , S. Schreiber 2R. Ischebeck 31 University of Hamburg, Germany2 DESY, Hamburg3 PSI, SwitzerlandsFLASH is a seeding FEL experiment at FLASH/DESY, to introduce a 30nm high harmonic gain(HHG)-based XUV-beam laser to the electron bunches of FLASH at the entrance of a 10mvariable-gap undulator. The temporal overlap between the electron beam and HHG is important forthe seeding process. The installation of a 3rd harmonic cavity at FLASH will provide a long highcurrent electron beam (at kA level) over ~ 600 fs Full-Width at Half- Maximum (FWHM) bunchduration. The duration of the HHG laser pulse will be about 30fs (FWHM). The desired overlap canbe achieved in steps. One approach will be to synchronize the drive laser (Ti: Sapphire, 800nm) ofHHG and the incoherent spontaneous synchrotron radiation of the undulator at a sub-picosecondprecision. In a following step the overlap can be improved by scanning within the sub-picoseconduncertainty. The possibility of using a streak camera to detect both the 800nm laser and thespontaneous undulator radiation pulses without perturbing FLASH user operation is investigated.To match the power levels, the laser beam has to be attenuated by several orders in magnitude. Thelayout of the experiment and preliminary simulation results of generation and transport of both lightpulses are presented.46

P14CONTROL OF THE POLARIZATION OF ATTOSECOND PULSES USINGA TWO-COLOR FIELDCamilo Ruiz 1,2 , David Hoffmann 1 , Ricardo Torres 1 , Luke Chipperfield 1and Jonathan P Marangos 11 Blackett Laboratory, Imperial College London, London SW7 2BW, UK1 Centro de Laseres Pulsados ultraintensos, Plaza de la Merced s/n 37006 ,Salamanca, SpainControl over the polarization of an attosecond pulse train is demonstrated theoretically by usingorthogonally polarized two-color fields. The carrier envelope phase (CEP) of the two pulses is usedas a control parameter to switch from linear polarization in two planes to elliptical polarization. Thecontrol mechanism is explained in terms of classical trajectories.In this paper we will address the control of the polarization and temporal structure of the attosecondpulses and APT by using two perpendicular fields of different frequencies overlapped in time. Theadvantage of the proposed scheme is its flexibility. Several distinct control scenarios can beobtained: a good degree of control over the polarization – from linear to elliptical – by adjusting theCEP of the two fields and, in the case of linear polarization, a simple way to change the temporalstructure of the APT obtained. Such pulses, and the required control over the CEP are nowavailable from state-of-the-art ultra intense few-cycle laser systems 1,2.________________________________________1 E. Goulielmakis et al., Single-Cycle Nonlinear Optics, Science 320, 1614 (2008).2 G. Cirmi, et al., Carrier-envelope phase stable, few-optical-cycle pulses tunable from visible tonear IR, J. Opt. Soc. Am. B 25, B62 (2008).47

Friday 1 st May15:00 – 16:45Afternoon session:Attosecond Electron Dynamics IIChair: P. Corkum48

ATTOSECOND STEERING OF ELECTRONIC MOTION IN ATOMS ANDMOLECULES VIA ~6 FS CE PHASE STABILIZED PULSESR. Gopal 1 , A. Rudenko 2 , M. Kremer 1 , B. Fischer 1 , K. Simeonidis 1 , R. Moshammer 1 , Th. Ergler 1 , M.Kurka 1 , K.U. Kühnel 1 , C. D. Schröter 1 , D. Bauer 1 , B. Feuerstein 1 , V. L. B. de Jesus 4 , O. Herrwerth 3 ,Th. Uphues 3 , M. Schultze 3 , E. Goulielmakis 3 , M. Uiberacker 3 , M. Lezius 3 , M. F. Kling 3 , J.Ullrich 1,21 Max-Planck-Institut für Kernphysik (MPIK) , Saupfercheckweg 1, D-69117 Heidelberg2 Max Planck Advanced Study Group at CFEL, D-22607 Hamburg3 Max-Planck-Institut für Quantenoptik (MPQ), Hans-Kopfermann-Str. 1, D-85748 Garching4 CFET de Química de Nilópolis, Rua Lucio Tavares 1045, Rio de Janeiro, BrazilUsing a reaction-microscope, three-dimensional electron and ion momentum ( P r ) spectra have beenrecorded for carrier-envelope-phase (CEP) stabilized few-cycle (~ 5-6 fs), intense (4⋅10 14 W/cm 2 )laser pulses (740 nm) interacting with atoms and molecules. In a collaborative effort experiments onHe atoms have been performed at the MPQ whereas the fragmentation of H 2 molecules wasinvestigated at the new CEP stabilized pump-probe facility at the MPIK.For He atoms preferential emission of low-energy electrons (E e < 15 eV) to either hemisphere isobserved as a function of the CEP. Clear interference patterns emerge in P r -space at CEPs withmaximum asymmetry, interpreted as attosecond holographic “self”-images of re-scattered electronwave-packets by means of a simple model and in line with previous theoretical predictions 1 . ForH 2 + molecules we do observe, for the first time and different from earlier measurements 2 , electronlocalisation in the 1ω and effective 2ω fragmentation channels depending on the kinetic energyrelease (KER) in general agreement with but at better significantly better contrast than predicted bytheory 3 . Moreover, we find the asymmetry varying as a function of the orientation of the moleculesand inspect CEP dependent coincident electron emission from the first step, i.e. ionizing the H 2molecule and starting the bound-state dynamics in H 2 + . Finally, we present results of wave-packetdynamic calculations, show data for more complicated molecules and envision future directions.1 D.G. Arbó et al. Phys. Rev. A 74, 063407 (2006).2M.F. Kling et al., Science 312 246 (2006).3V. Roudnev and B. D. Esry, PRA 76, 023403 (2007).49

WAVELENGTH DEPENDENCE OF HIGH-HARMONIC GENERATIONK. L. Ishikawa 1,2 , K. Schiessl 3 , E. Persson 3 , J. Burgdörfer 3 , E. J. Takahashi 4 , K. Midorikawa 4 ,1 RIKEN Computational Science Research Program, Saitama, Japan2 PRESTO, Japan Science and Technology Agency, Saitama, Japan3 Institute for Theoretical Physics, Vienna University of Technology, Vienna, Austria, EU4 Extreme Photonics Research Group, RIKEN Advanced Science Institute, Saitama, JapanWe investigate the dependence of the yield of the high-harmonic generation (HHG) on wavelengthλ of a few-cycle laser pulse. Superimposed on a smooth power-law dependence observedpreviously, we find surprisingly strong and rapid fluctuations on a fine λ scale 1 . Using theLewenstein model of HHG, we identify the origin of these fluctuations in terms of quantum pathinterferences with many returning orbits significantly contributing.We also investigate the connection of the fine-scale oscillations to the well-known channel closing(CC) effect. By studying the simultaneous variations with intensity and wavelength, differentmodels for the interference of channel closing peaks can be tested. Contrary to theoreticalpredictions for short-range potentials, the peaks are located neither at nor just below the CCcondition, but a significant shift is observed 2 . The long Coulomb tail of the atomic potential isidentified as the origin of the shift 3 .In addition, we study the scaling with λ of HHG, under the simultaneous irradiation of the boosterXUV pulse. Surprisingly, at fixed ponderomotive energy and ionization, the harmonic yield isnearly independent of λ. We identify one of its origins as the initial spatial width of the statesexcited by the booster pulse, making the wavepacket spreading less prominent. We also establishthat the distribution of the harmonic energy up to the cutoff has a contribution proportional to λ -2 .1 K. Schiessl et al. Quantum path interference in the wavelength dependence of high-harmonic generation. Phys. Rev.Lett. 99, 253903 (2007).2 K. Schiessl et al. Wavelength dependence of high-harmonic generation from ultrashort pulses. J. Mod. Opt. 55, 2617-2630 (2008).3 K. L. Ishikawa et al. Fine-scale oscillations in the wavelength- and intensity-dependence of high-harmonicgeneration: connection with channel closings. Phys. Rev. A, in press (2009).50

GENERATION AND APPLICATIONS OF ATTOSECONDPULSE TRAINSE. Mansten, J. M. Dahlström, K. Klünder, M. Swoboda, Xinkui He, J. Schwenke,P. Johnsson, J. Mauritsson, A. L’HuillierDepartment of PhysicsLund UniversityWhen an intense laser field interacts with an atomic gas, nonlinear processes take place, leading tothe emission of a sequence of extremely short pulses of light, of attosecond duration. We willdiscuss in this talk a few techniques to frequency shape and tune attosecond pulses, as well as tomanipulate and characterize attosecond pulse trains in different conditions. Examples ofapplications of attosecond pulses and pulse trains will be presented.51

MACROSCOPIC EFFECTS IN SINGLE ATTOSECOND PULSEGENERATIONValer Tosa 1 , Carlo Altucci 2 and Raffaele Velotta 21 Natl. Inst. R&D Isotopic Molecular Technologies, Cluj-Napoca, Romania2 CNISM-Dipartimento di Scienze Fisiche, Università di Napoli “Federico II”, Napoli, ItaliaThe generation of a single isolated attosecond pulse (SAP) have been mainly achieved by means ofHigh Harmonic Generation (HHG) in gas. Usually SAP can only be obtained if one is able to selectthe HHG emission within half a cycle of the laser field. We discuss here some of the macroscopiceffects which are responsible for producing clean isolated pulses lasting few hundreds ofattoseconds. In particular we consider the polarisation gating scheme 1 and show that the gating andthe ionization induced depletion usually producemore attosecond pulses of radiation at single dipolelevel. We show that non-homogeneous HHG in theinteraction region as well as phase matchedharmonic field propagation, contribute to the SAPgeneration at macroscopic level.Non-adiabatic, three dimensional (3D) propagationof fundamental and harmonic fields through to thegas target has been accounted for by extending aprevious model to the case of two fields, and bynumerically integrating the correspondingpropagation equations for both fundamental andharmonic fields.The proposed experimental configurations areanalysed against the variation of various-4 -2 4t/T 0Fig. 1. The temporal SAP structure for±30% intensity variation1C. Altucci, V. Tosa, R. Velotta, Phys Rev A 75, 061401R (2007)2 C. Altucci, R. Esposito, V. Tosa, R. Velotta, Opt. Lett. 33, 2943 (2008)experimental parameters in view of their applicability to commercially available laser systems. Thedata in Fig. 1 demonstrate that in the polarization gating scheme recently 2 proposed the laserintensity may vary as much as 30% without altering the SAP structure. In the same schemehowever, the radial variation of the frequency modulation parameter (chirp) is limited to a 3-5%range.765432100.7 I 0I 01.3 I 052

Friday 1 st May15:00 – 16:45Afternoon session:Structural Dynamics of Complex Systems IChair: M. Chergui53

ULTRA-FAST PROBING OF SHOCK-COMPRESSED MATTER WITH X-RAY THOMSON SCATTERINGSiegfried GlenzerLawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551, USA,E-mail: glenzer1@llnl.govWe have developed accurate x-ray scattering techniques to measure the physical properties of denseplasmas. One future challenge is the application of this technique to characterize compressed mattersuch as produced in inertial confinement fusion experiments on the National Ignition Facility (NIF)where hydrogen and beryllium will approach extremely dense states of matter of up to 1000 g/cc.In this regime, present experiments 1,2 show that density and compressibility can be directlymeasured from the spectral broadening of the Compton scattered spectrum of a high-energy x-raysource. This technique is model-independent and based on first principles allowing us to determinethe density from the spectral shape of the scattering spectrum that is directly reflecting the electronvelocity distribution. For Fermi-degenerate plasmas, the spectrum thus provides the Fermi energy.In this talk, Compton scattering 3 and Plasmon scattering 4 experiments on shock-compressed matterwill be presented. Besides extracting the standard plasma parameters, density and temperature,forward scattering is shown to yield new observables such as a direct measure of collisions,structure factors, and the dispersion of plasma waves in quantum plasmas.*This work performed under the auspices of the U.S. Department of Energy by LawrenceLivermore National Laboratory under Contract DE-AC52-07NA27344.1 A. L. Kritcher et al., Science, 322,69 (2008).2 H. J. Lee et al., Phys. Rev. Letters, in print (2008).3 S. H. Glenzer et al., Phys. Rev. Letters 90, 175002 (2003).4 S. H. Glenzer et al., Phys. Rev. Letters 98, 065002 (2007).54

ULTRAFAST DYNAMICS AND PHASE TRANSITION IN PHOTOEXCITEDBISMUTH CRYSTALDavide Boschetto 1 , Denis Morineau 2 , Antoine Rousse 1 , Eugene Gamaly 3 , Andrei V. Rode 31 Laboratoire d’Optique Appliquée, ENSTA/Ecole Polytechnique,Chemin de la Hunière, 91761 Palaiseau, France2 Institut de Physique de Rennes, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes,France3 Laser Physics Centre, The Australian National University,Canberra, ACT 0200, AustraliaThe ability to modify and control the physical properties of matter by using any external excitationis a very exciting challenge from both scientific and technological point of view. When usingfemtosecond laser pulse for excitation, the system is set in a highly non-equilibrium state, in whichthe interaction between all the degrees of freedoms of the crystal can produce transitions into newphases different from equilibrium ones. Following the relaxation dynamics with the required timeresolution of few tens of femtoseconds is a key step in order to understand the pathway of any ofthose transitions. However, the characterization of any transient state requires the measurement ofthe dielectric function dynamics, which has the signature of the band structure modifications.We applied two-probes set-up for recovering the dynamics of dielectric function at 800 nm ofphoto-excited bismuth, in order to characterize the transient state following both the coherentphonon oscillation mode and the electron-phonon thermalization process [1]. The results arecompared with those from static ellipsometry measurement as function of the crystal temperature.Just after the photo-excitation, the crystal is driven into a more metallic state, as expected by theinjection of electrons into the conduction band, and coherent phonon mode starts. However, afterthe electron-phonon thermalization that occurs in around 20 ps, the results suggest that bismuthcrystal undergoes a photo-induced phase transition toward a new transient metastable phase.____________________________________________1 D. Boschetto et al., Small Atomic Displacements Recorded in Bismuth by the Optical Reflectivity of FemtosecondLaser-Pulse Excitations, Physical Review Letters 100, 027404 (2008).55

X-RAY CROSS CORRELATION ANALYSIS UNCOVERS HIDDEN LOCALSYMMETRIES IN DISORDERED MATTERP. Wochner 1 , C. Gutt 2 , T. Autenrieth 2 , T. Demmer 1 , V. Bugaev 1 , A. Díaz Ortiz 1 , A. Duri 2 , F.Zontone 3 , G. Grübel 2 , H. Dosch 1,21 Max-Planck-Institut für Metallforschung, Heisenbergstrasse 3, D-70569 Stuttgart, Germany2 DESY, Notkestrasse 85, D-22607 Hamburg, Germany3 ESRF, 6 rue Jules Horowitz BP 220, 38043 Grenoble Cedex 09, FranceDisordered matter, such as glasses and liquids, does not exhibit translational symmetry and in turnis able to accommodate different local symmetries in the same system, among them the icosahedrallocal order, which belongs to the forbidden motifs in periodic structures.To explore the different local symmetries in disordered matter we need to go beyond the standardpair correlation analysis. Using our newly developed 4-point x-ray cross correlation analysis(XCCA) concept together with brilliant coherent x-ray sources, we have been able to access andclassify the otherwise hidden local order within disorder in colloidal glasses 1 . The emerging localsymmetries are coupled to distinct momentum transfer (Q) values, which do not coincide with themaxima of the amorphous structure factor. Four-, six-, ten- and, most prevailing, five-foldsymmetries are observed. The observation of dynamical evolution of these symmetries forms aconnection to dynamical heterogeneities in glasses, which is far beyond conventional diffractionanalysis.The XCCA concept opens up a fascinating view into the world of disorder and will definitely allow,with the advent of free electron x-ray lasers, an accurate and systematic experimentalcharacterization of the structure of the liquid and glass states. By analyzing single laser shot specklediffraction patterns the detailed structural dynamics can be studied on a shot by shot basis or viapump-probe technique. The combination of short-pulse XFEL radiation and large 2D-detectorarrays will also open up the window for the study of nano-powders and transient complex molecularstructures in solution.1 P. Wochner et al. X-ray Cross Correlation Analysis Uncovers Hidden Local Symmetries in Disordered Matter.Manuscript submitted.56

ULTRAFAST DYNAMICAL RESPONSE OF THE PROTOTYPE MOTTCOMPOUND V 2 O 3B. Mansart 1 , D. Boschetto 2 and M. Marsi 11 Laboratoire de Physique des Solides, UMR 8502, Université Paris-Sud, 91405 Orsay, France2 Laboratoire d’Optique Appliquée, ENSTA, CNRS, Ecole Polytechnique, 91761 Palaiseau, FranceCr-doped V 2 O 3 is considered as a prototype Mott-Hubbard system, presenting a first order metalinsulatorMott transition.. In this work, we used femtosecond time-resolved pump-probe reflectivityto study this complex material, extending for the first time the use of this technique to the study ofseveral points of its phase diagram. In particular, we explored the difference between theparamagnetic metallic and paramagnetic insulating phases, which have been the subject ofnumerous theoretical and experimental studies, including some recent ones in our laboratory 1 .Our results show that the transient reflectivity of Cr-doped V 2 O 3 presents a complexphenomenology, characterized by an ultrafast electronic excitation followed by coherentoscillations corresponding to optical and acoustic lattice vibrations. These features depend onsurface crystallographic orientation, light polarization and on Cr doping of the specimen - i.e. on itsphase across the Mott transition - as we found after an extensive and systematic series ofmeasurements.We will discuss these results and their implications for our understanding of this model Mott-Hubbard system, also in the light of some recent and parallel synchrotron radiation basedexperiments which indicate that in some portions of the phase diagram the metallic and insulatingstate can coexist on a microscopic scale, thus affecting the dynamical evolution of the system.1 P. Limelette et al. Universality and critical behavior at the Mott transition. Science 302, 89 (2003).57

Saturday 2 nd May15:00 – 16:45Morning session:Structural Dynamics of Complex Systems IIChair: S. Glenzer58

ULTRAFAST MANIPULATION OF MAGNETIZATIONJoachim StöhrStanford Synchrotron Radiation Lightsource and PULSE CenterStanford University, Stanford, California, USASwitching of the magnetization of a ferromagnet between two opposite directions can be initiatedby an external magnetic field generated by current flow through wires or by injecting a spinpolarized current directly into the magnetic material. In the pursuit of smaller and faster switchingdevices, currentless reversal of the magnetization would be highly desirable. This would avoidenergy dissipation by current flow and overcome impedance induced speed limitations. It may thenbe possible to extend the present switching speed of about 100 ps into the femtosecond regime.In this talk I will discuss schemes of reversing the magnetization of a ferromagnet by electric fieldsalone, without charge or spin currents or external magnetic fields. The concept is based on using astrong (eV/atom) and short (femtoseconds) electric field pulse to distort the atomic charge densityalong the direction of the linearly polarized E field. The charge distortion in conjunction with thespin-orbit interaction can then lead to a transient magneto-electronic anisotropy which can beutilized to redirect the magnetization. The switching process is initiated and predetermined by theorientation, magnitude, and temporal length of the E-field writing pulse.I will also present experimental data that support the proposed concept. In particular, we usedultrashort (70 fs) and ultrastrong (up to 20 GV/m) fields generated by a compressed relativisticelectron bunch to manipulate the magnetization in a magnetic thin film sample 1 . Such pulsesgenerate true half-cycle THz fields that imprint a characteristic magnetization pattern into thesample. Analysis of the pattern clearly reveals the existence of a magneto-electronic anisotropygenerated by the E field, superimposed on that due to the B field. Since the switching torque on themagnetization is quadratic in E but linear in B, we propose that a full cycle THz pulse, where the Bfield contribution cancels, could be employed for E field only switching.1 J. Stöhr and H. C. Siegmann, Magnetism: From Fundamentals to Nanoscale Dynamics, Springer 2006.59

ULTRAFAST ELECTRON AND SPIN DYNAMICS IN FERROMAGNETSH.A. DürrHelmholtz Zentrum Berlin, BESSY,Albert Einstein-Str. 15, 12489 Berlin, GermanyThe interplay between electronic, spin and lattice degrees of freedom often determines the functionof complex materials such as ferromagnets, high T C superconductors, colossal magnetoresistive andmultiferroic oxides. Charge and orbital ordering phenomena can lead to metal-insulator transitionswith temperature or chemical doping. These phenomena can ideally be studied using soft x-rayswhich probe directly the valence orbitals responsible for electronic and spin order. Time resolvedoptical pump – x-ray probe studies offer the exciting prospect of observing the flow of energy andangular momentum in real time 1 . Here I will concentrate on ferromagnetic materials where x-raydichroism is a unique probe of the spin order while x-ray resonant scattering provides direct accessto orbital and charge order. Examples of ultrafast laser induced demagnetization of Gd and laserinduced melting of charge order in magnetite will be described.1 C. Samm et al. Femtosecond modification of electron localization and exchange of angular momentum in Ni, NatureMaterials 6, 740 (2007).60

ULTRAFAST ELECTRONIC PROCESSES IN CLUSTERSJ. RostMax-Planck-Institut fuer Physik komplexer SystemeNoethnitzer Str. 38, D-01187 DresdenAttosecond pulses extend our capabilities to excited electrons in various ways. Simultaneous(within the length of an attosecond pulse) excitation of several electrons becomes in principlepossible but requires also roughly equivalent bound electrons. This is the case in rare gas clusters.The resulting, unusual, excitation dynamics will be discussed. In the second part of the talk a newmechanism of ultrafast formation of an electronic nanoplasma will be introduced, which does notrequire attosecond pulses. It relies on a substantial breaking of the spherical plasma symmetrywhich can be easily induced by seed atoms (molecules) 1 .1A. Mikaberidze, U. Saalmann, J. M. Rost, Phys. Rev. Lett 102, 128102 (2009).61

TR-PHOTOEMISSION ELECTRON MICROSCOPY - NANOSCALESPECTROSCOPY WITH FEMTOSECOND RESOLUTIONMartin AeschlimannDepartment of Physics and Research Center OPTIMAS, University of Kaiserslautern, GermanyIn this contribution I will present an experimental scheme capable of monitoring ultrafast dynamicson nanoscale dimensions. Over the last decade there have been numerous attempts to combinescanning probe microscopy and femtosecond pump-probe techniques to realize an ultrafastmicroscope with nanometer resolution. So far, no satisfactory solution has been presented. Ourapproach applies the technique of time-resolved 2PPE to a conventional photoemission electronmicroscope (PEEM) 1 . In this configuration the photoemission signal collected by the PEEMdetector is related to the lifetime of excited (hot) electrons at the sample surface.The potential of this technique will be illustrated by two examples: In a first study the time-resolvedPEEM technique is used to map the dynamical response of supported metal clusters (

OPTICAL AND X-RAY STUDIES OF THE ULTRAFAST DYNAMICS OFMOLECULAR SYSTEMS IN LIQUIDSM. CherguiLaboratoire de Spectroscopie Ultrarapide (LSU), Ecole Polytechnique Fédérale de Lausanne,CH-1015 Lausanne SwitzerlandThe details of the photoinduced dynamics of molecular systems in liquids has been investigated bya combination of different ultrafast spectroscopic techniques, which include transient absorption inthe visible and UV (down to 300 nm), polychromatic femtosecond fluorescence measurements inthe range from 300 to 800 nm, and picosecond and femtosecond hard X-ray absorptionspectroscopy. These approaches allow us to probe both the molecular structure of the systems, butalso the underlying electronic structure changes that trigger them. We will present examples on thespin and structural dynamics in Fe(II)-based molecular complexes, 1,2 on the dynamics of electronicsolvation 3,4 and on the bond formation in bimetallic complexes 5 .1 W. Gawelda et al. Structural determination of a short-lived Iron(II) Complex by Picosecond X-ray AbsorptionSpectroscopy. Phys. Rev. Lett. 98 (2007) 057401.2 C. Bressler et al. Femtosecond XANES of the light-induced spin crossover dynamics in an Iron(II)-complex Science323 (2009) 489.3 Van Thai Pham et al. Observation of the solvent shell reorganisation around electronically excited atomic solutes bypicosecond X-ray absorption spectroscopy. J. Am. Chem. Soc. 129 (2007) 1530.4 C. Bressler et al. Exploiting EXAFS and XANES for Time-Resolved Molecular Structures in Liquids. Z. für Kristall.223 (2008) 307.5 R. M. van der Veen et al. Structural determination of photochemically active diplatinum molecule by time-resolvedEXAFS spectroscopy. Ang. Chem. Int. Ed. (in press).63

“MAKING THE MOLECULAR MOVIE”: QUEST FOR THE STRUCTURE-FUNCTION CORRELATION OF BIOLOGYR.J. Dwane MillerDepartments of Chemistry and Physics,Institute for Optical SciencesUniversity of Toronto,Toronto, Ontario, Canada, M5S 3H6dmiller@lphys.chem.utoronto.caFemtosecond Electron Diffraction harbours great potential for providing atomic resolution tostructural changes as they occur, essentially watching atoms move in real time ― directly observetransition states. This experiment has been referred to as "making the molecular movie" and hasbeen previously discussed in the context of a classic gedanken experiment, outside the realm ofdirect observation. With the recent development of femtosecond electron pulses with sufficientnumber density to execute nearly single shot structure determinations, this experiment has beenfinally realized. A new concept in electron pulse generation was developed based on a solution tothe N-body electron propagation problem involving up to 10,000 interacting electrons that has ledto a new generation of extremely “bright” electron pulsed sources that minimizes space chargebroadening effects. Previously thought intractable problems of determining t=0 and fullycharacterizing electron pulses on the femtosecond time scale have now been solved through theuse of the laser pondermotive potential to provide a time dependent scattering source.Synchronization of electron probe and laser excitation pulses is now possible with an accuracy of10 femtoseconds to follow even the fastest nuclear motions. The camera for the “molecular movie”is now in hand with electron based sources. Atomic level views of the simplest possible structuraltransition have been obtained under strongly driven conditions (up to warm dense matterconditions) as well as electronically driven atomic motions as a direct probe of the many bodyelectron correlation effects on the forces related to bonding. The overall objective is to extend thisapproach to biological systems to directly observe the structure-function correlation ⎯ thefundamental underpinnings of biology.64

QUANTUM DIMENSION OF PHOTOSYNTHESISREVEALED BY POWERFUL NEW LASER TECHNIQUEIan P. Mercer 1 , Yasin C. El-Taha 2 , Nathaniel Kajumba 2 , Jonathan P. Marangos 2 , John W. G. Tisch 2 ,Mads Gabrielsen 3 , Richard J. Cogdell 3 , Emma Springate 4 & Edmund Turcu 41School of Physics, Centre for Synthesis and Chemical Biology,University College Dublin, Dublin 4, Ireland.2 Quantum Optics and Laser Science Group, Blackett Laboratory,Imperial College, London, UK.3 Biochemistry and Molecular Biology, Faculty of Biomedical and Life Sciences,University of Glasgow, Glasgow, UK.4Central Laser Facility, STFC Rutherford Appleton Laboratory, Didcot, UK.Coherent electronic motion may play a role in the remarkably efficient energy transfer inphotosynthetic macromolecules. Coherent optical four wave mixing has been used widely to obtaininformation on the timescales of energy transfer in complex molecular systems. However, theinterpretation of such measurements is difficult in particular where chromophores are stronglycoupled, such as in photosynthetic systems, and new methods are required for an improvedfeedback to simulation.We present a novel non-linear optical method, Angle-Resolved Coherent (ARC) wave mixing, thatseparates out coherent electronic couplings from energy transfers in an instantaneous twodimensionalmapping 1 . For this we use a high energy, ultra-broadband hollow fibre laser source 2 .The power of the new method is demonstrated with the light harvesting complex II (LH2) of purplebacteria at ambient temperature. We reveal a coherent quantum electronic beating with a timeorderedmatter-selection of transition energies. We show that the position of a feature can mapuniquely to each of the four laser beam interaction energies that produce the signal and we observea correlation between excitation and emission energies in the protein.1 I.P. Mercer et al., Phys. Rev. Lett. 102, 57402 (2009).2 J. S. Robinson et al., Appl. Phys. B 85, 525 (2006).65

Sunday 3 rd May9:00 – 11:30Morning session:New Methods and SourcesChair: J. Rossbach66

WATER WINDOW X-RAY GENERATION BY PHASE-MATCHED HIGHHARMONICS WITH NEUTRAL MEDIAKatsumi MidorikawaExtreme Photonics Research Group, RIKEN2-1 Hirosawa, Wako, Saitama 351-0198, Japankmidori@riken.jpHigh-order harmonics generation (HHG) provides highly coherent ultrafast soft x-ray pulses from atabletop laser system. HHG has been attracting much attention due to their unique properties, suchas ultrashort pulse duration, high peak intensity and brightness, wide tunability, and low equipmentcost. Although the harmonics photon energy attained within the ”water window” region by usingsub-10 fs Ti:sapphire laser as a driving source, the generation efficiency of the water windowwavelength harmonics was limited by the dephasing of the atomic dipoles and the plasmadefocusing of the laser pulse due to free electrons, because the laser intensity exceeds the ionizationthreshold of the target gases for 800 nm driving lasers.Here we report on the generation of coherent water-window x-ray by phase-matched highharmonics in neutral media. The spectral cutoff of HHG is approximately given by Ip + 3.17Up,where Ip is the ionization potential and Up is the ponderomotive energy. Since the ponderomotiveenergy is proportional to not only the pump laser intensity but also the square of the driving laserwavelength, a longer-wavelength intense infrared laser allows generating higher-energy harmonicphotons without ionization. We have demonstrated the efficient generation of a coherent x-ray highorderharmonics in the water window region using an IR driving laser and a neutral rare-gasmedium. Our proposed procedure for generating the water window x-ray is efficient and scalable inoutput yield, which provides us with the HHG parameters required for the imaging of live cells.67

LINAC COHERENT LIGHT SOURCE AND SINGLE MOLECULEIMAGINGSébastien BoutetLinac Coherent Light Source, SLAC National Accelerator LaboratoryThe Linac Coherent Light Source (LCLS), coming on-line in the Summer of 2009, will become thefirst ever hard x-ray Free-Electron Laser (FEL). It will utilize the 13 GeV electron beam from thelast km of the 3 km long linear accelerator on the site of the SLAC National Accelerator Laboratoryto produce hard x-ray pulses containing 10 12 photons or more in less than 100 femtoseconds. Theincredible brightness of this new source will make it a unique tool with unexplored discoverypotential. Among the novel scientific opportunities hard x-ray FELs offer, the possibility ofobtaining snapshot images of single non-periodic objects, especially biological samples, hasgenerated a tremendous level of excitement. The extremely short duration and high intensity of thex-ray beam promises to minimize radiation damage to biological samples during the pulse and toallow high resolution imaging of non-crystalline objects.In this talk, I will discuss the LCLS and the status of its commissioning as the start of operationsrapidly approaches. I will briefly introduce the experimental instruments being built for LCLS thatwill utilize to its fullest the unique properties of the beam in areas of ultra-fast science. Finally, Iwill discuss in greater detail the plans for the single molecule imaging instrument along with someof the recent results validating the techniques required for such experiments.68

TWO COLOUR AND TWO PHOTON IONIZATION PROCESSES ININTENSE EUV AND OPTICAL FIELDS AT ‘FLASH’J. T. Costello 1 , J. Dardis 1 , P. Hayden 1 , P. Hough 1 , T. J. Kelly 1 , E. T. Kennedy 1 ,V. Richardson 1 , A. A. Sorokin 2 , M. Richter 2 , S. Duesterer 3 , W. B. Lee 3 , K. Tiedke 3 ,J. Feldhaus 3 , R. Taieb 4 , A. Maquet 4 , H. van der Hart 5 , A. N. Grum-Grzhimailo 6 ,E. V. Gryzlova 6 , S. I. Strakhova 6 , D. Cubaynnes 7 and M. Meyer 71 School of Physical Sciences & NCPST, Dublin City University, Dublin 9, Ireland2 Physikalisch-Technische Bundesanstalt, Abbestrasse 2-12, D-10587 Berlin, German3 HASYLAB at DESY, Notkestr. 85, D-22607 Hamburg, Germany4 UPMC, Universite Paris 06, CNRS, UMR 7614, LCPMR, 75231 Paris Cedex 05, France5 Dept. Of Applied Mathematics and Theoretical Physics, QUB, Belfast, BT7 1NN, N. Ireland6 Institute of Nuclear Physics, Moscow State University, Moscow 119991, Russia7 LIXAM, UMR 8624, Universite Paris Sud, Batiment 350, 91405 Orsay Cedex, FranceThe EUV research domain is undergoing a period of unprecedented growth, motivated not just by adesire to educidate the fundamental light-matter interaction on atomic time and spatial scales butalso by the prospects that the field offers to address impending bottlenecks in semiconductormanufacturing on the nanoscale and improve molecular scale imaging with its unfolding benefits inthe health and biomedial sciences. The key outcome of the EUV photon-matter interaction isphotoionization and, in the case of weak EUV fields, theory and experiment have developedsymbiotically to provide a deep understanding of the underlying photon-electron processes even inhighly correlated systems. The complementary field of ionization in intense optical laser fields hasrevealed many new dynamical processes such as multi-photon, above-threshold and optical-fieldionization as well as high harmonic generation [1]. Now the development of EUV Free ElectronLaser facilities such FLASH [2] signals a new era for the study atomistic systems in not just intensebut also in ultrahigh frequency fields [3,4]. In this talk I will provide an update on the FLASHfacility and briefly summarise its current performance parameters. Experimental topics will includea demonstration experiment on dissociation of H 2 and photoionization of rare gas atoms in intenseEUV and superposed EUV/optical fields. The talk will wrap up with some perspectives onexperiments following the imminent FLASH upgrade (2010) and to be carried out at LCLS (2009).__________________________1 Corkum PB, Krausz F, Attosecond Science, Nature Physics, Vol: 3, 381 (2007).2 Ackermann W et al, Operation of FLASH in the Water Window, Nature Photonics, Vol: 1, 336 (2007).3 Costello J T Photoionization Experiments with FLASH, J. Phys. Conf. Ser. Vol: 88 012057 (2007).4 Bostedt C et al., Experiments at FLASH, Nucl. Inst. Meth. in Res. A doi:10.1016/j.nima.2008.12.202 (2009).69

INVESTIGATION OF ULTRAFAST STRUCTURAL CHANGES INCOMPLEX CHEMICAL SYSTEMS USING X-RAY FELSTh. Tschentscher 1 , M. Messerschmidt 2 , S. Techert 33 European XFEL, c/o DESY, Notkestraße 85, 22603 Hamburg, Germany2 DESY, Notkestraße 85, 22603 Hamburg, Germany3 MPI Biophysical Chemistry, Am Faßberg 11, 37070 Göttingen, GermanyResearch using ultrashort, intense and coherent x-ray pulses providing by forth-coming x-ray freeelectronlaser (FEL) facilities enables new insight into the structural and dynamic behaviour ofmolecules, clusters, plasmas or solid state matter. A time resolution in the regime of 100femtoseconds and below is well suited to investigate ultrafast electronic and structural dynamics ofvery different origin. As an example for one area of research the application to small moleculechemical systems will be discussed in this presentation. X-ray diffraction, scattering and imagingtechniques provide the necessary spatial resolution to study structural properties at the relevantatomic length scale, e.g. to investigate the time evolution of the geometrical structure of moleculesduring the course of transitions. Spectroscopic techniques can further be used to study electronicexcitations. Using hard x-rays and investigating crystalline samples will enable to exploit x-raystructure determination techniques achieving very high sensitivity and spatial resolution. Currentlythis research is limited by the availability of x-ray sources providing at the same time femtosecondtime-resolution, adequate resolution and significant photon flux. Hard x-ray FELs will change thissituation dramatically.Results of pre-cursor experiments investigating ultrafast dynamics in small molecules using hard x-ray synchrotron radiation with reduced time resolution and soft x-ray FEL radiation with reducedspatial resolution will be presented. Issues to be addressed in terms of instrumentation using FELswill be discussed. In this context also concepts for applying the high repetition rate of the EuropeanXFEL to a variety of challenging scientific problems and to operating many experiments in parallelwill be introduced.70

Sunday 3 rd May, 11.30 – 12.30Round table discussion (coordinator: J. Marangos):Future Challenges and Prospects forUltra-Fast Dynamics Imaging.71

List of ParticipantsPeter Abbamonte University of Illinois abbamonte@mrl.uiuc.eduMartin Aeschlimann University of Kaiserslautern ma@physik.uni-kl.deCarlo Altucci University of Naples "Federico II" caltucci@unina.itMuhammadTanveerBaig University of Siegen tanveer_pucit@yahoo.comSarah Baker Imperial College London sarah.baker@imperial.ac.ukLuis Banares Universidad Complutense de Madrid banares@quim.ucm.esDavid Bartram Imperial College London david.bartram@gmail.comJulienBeaudoinBertrandUniversity of Ottawajulien.bertrand@nrc.caDavideBoschettoLaboratoire d'Optique Appliquée, ENSTA/EcolePolytechniquedavide.boschetto@ensta.frSebastien Boutet SLAC National Accelerator Laboratory sboutet@slac.stanford.eduFrancesca Calegari Politecnico di Milano francesca.calegari@polimi.itMajed Chergui EPFL - LSU majed.chergui@epfl.chPaul Corkum University of Ottawa Paul.Corkum@nrc.caPietro Paolo Corso Università di Palermo corso@fisica.unipa.itJohn Costello Dublin City University john.costello@dcu.ieDelphine Darios Imperial College London delphine.darios@imperial.ac.ukRebeca de Nalda Instituto de Quimica Fisica Rocasolano (CSIC) r.nalda@quim.ucm.esZsolt Diveki CEA-Saclay zsolt.diveki@cea.frReinhard Dörner Institut für Kernphysik, University of Frankfurt doerner@atom.uni-frankfurt.deHermann Dürr Helmholtz Zentrum Berlin hermann.duerr@bessy.deFederico Ferrari Politecnico di Milano federico.ferrari@mail.polimi.itCarla F. M. Faria University College London c.faria@ucl.ac.ukEmilio Fiordilino Università di Palermo fiordili@fisica.unipa.it72

Gregory Gitzinger Consejo Superior de Investigaciones Cientificas coach_gg83@hotmail.comSiegfried Glenzer Lawrence Livermore National Laboratory glenzer1@llnl.govKenichi Ishikawa RIKEN ishiken@riken.jpMisha Ivanov Imperial College London m.ivanov@imperial.ac.ukMossy Kelly Dublin City University mossy.kelly@gmail.comReinhard Kienberger Max Planck Institute of Quantum Optics reinhard.kienberger@mpq.mpg.deJoukoKorppi-TommolaUniversity of Jyväskyläktommola@jyu.fiManfred Lein University of Kassel lein@physik.uni-kassel.deFranck Lépine LASIM/CNRS lepine@lasim.univ-lyon1.frAnne L'Huillier Lund University Anne.LHuillier@fysik.lth.seChii-Dong Lin Kansas State University cdlin@phys.ksu.eduMatteo Lucchini Politecnico di Milano matteo.lucchini@mail.polimi.itBarbara Mansart Laboratoire de Physique des Solides mansart@lps.u-psud.frJon Marangos Imperial College London j.marangos@imperial.ac.ukMoritz Meckel Institut fuer Kernphysik, Univ. Frankfurt meckel@atom.uni-frankfurt.deIan Mercer University College Dublin ian.mercer@ucd.ieMarco Micciarelli University of Naples "Federico II" marco.miccia@libero.itKatsumi Midorikawa RIKEN kmidori@riken.jpDwayne Miller University of Toronto dmiller@lphys.chem.utoronto.caStefano Orlando CNR - IMIP stefano.orlando@imip.cnr.itClaudio Pellegrino Department of Physics and Astronomy, UCLA cpellegrini@roadrunner.comImmacolata Procino University College London i.procino@ucl.ac.ukVincent Richardson Dublin City University vincent.richardson2@mail.dcu.ieJoerg Rossbach University of Hamburg & DESY joerg.rossbach@desy.deValerio Rossi Albertini National Research Council valerio.rossi@artov.ism.cnr.it73

Jan Michael Rost MPI for the Physics of Complex Systems rost@pks.mpg.deCamilo Ruiz University of Salamanca camilo@usal.esHirofumi Sakai University of Tokyo hsakai@phys.s.u-tokyo.ac.jpPascal Salieres CEA-Saclay pascal.salieres@cea.frGiuseppe Sansone Politecnico di Milano giuseppe.sansone@polimi.itAndrew Shiner National Research Council andrew.shiner@nrc.caOlgaSmirnovaMax-Born-Institute for Nonlinear Optics andShort pulse Spectroscopyolga.smirnova@mbi-berlin.deEmma Springate STFC Rutherford Appleton Lab emma.springate@stfc.ac.ukHenrik Stapelfeldt University of Aarhus henriks@chem.au.dkJoachim Stohr Stanford University and SLAC stohr@slac.stanford.eduRoxana Tarkeshian Desy roxana.tarkeshian@desy.deJohn Tisch Imperial College London john.tisch@imperial.ac.ukValer Tosa Natl. Inst. R&D Isotopic Molecular Technologies tosa@itim-cj.roThomas Tschentscher European XEL thomas.tschentscher@xfel.euKiyoshi Ueda Tohoku University ueda.kiyoshi@gmail.comJens Uhlig Lund University jens.uhlig@chemphys.lu.seJoachim Ullrich Max-Planck-Institut für Kernphysik c.ries@mpi-hd.mpg.deRaffaele Velotta University of Naples "Federico II" rvelotta@unina.itDavid Villeneuve National Research Council david.villeneuve@nrc.caCaterina Vozzi Politecnico di Milano caterina.vozzi@polimi.itPeter Wochner Max-Planck-Institute for Metals Research wochner@mf.mpg.deHans Jakob Wörner National Research Council Hans.Worner@nrc.ca74