Publication in Physical Review Letters of the article entitled "Mechanism of delayed double ionization in a strong laser field" by F. Mauger, A. Kamor, C. Chandre and T. Uzer.

Focus:
The simple man picture of an electron which is preionized by a strong linearly polarized laser field and hurled back to the core region where it interacts with the remaining ion was shown to be very effective in explaining abnormally abundant ionization rates as well as high harmonic generation. The returning electron collides with the remaining one, and exchange kinetic energy in order to release it from the Coulomb interaction with the nucleus as in a billiard or petanque game. In this picture, this interaction leads to a little (if any) time delay between the recollision and the subsequent ionization. However, a closer inspection of double ionizations has revealed an unexpected route to double ionization where the time delay between the recollision and subsequent ionization is unexpectedly long, commonly labeled as Recollision Excitation with Subsequent Ionization (or RESI for short). In our Letter, we analyze the mechanisms of delayed double ionization and identify the dynamical structures that regulate this phenomenon. We show that this RESI route to double ionization is a manifestation of Hamiltonian chaos.

Reference:
Publication: F. Mauger, A. Kamor, C. Chandre and T. Uzer - Mechanism of delayed double ionization in a strong laser field - Physical Review Letters 108, 063001 (2012)
Abstract: When intense laser pulses release electrons nonsequentially, the time delay between the last recollision and the subsequent ionization may last longer than what is expected from a direct impact scenario [“Recollision Excitation with Subsequent Ionization” (RESI)]. We show that the resulting delayed ionization stems from the inner electron being promoted to a sticky region. We identify the mechanism that traps and releases the electron from this region. As a signature of this mechanism, we predict oscillations in the ratio of RESI to double ionization yields versus laser intensity.

Volume 17, Issue 5, Pages 1987-2232 (May 2012)

Edited by:
C. Chandre
E. Tassi
J.-L. Thiffeault

This special issue of Communications in Nonlinear Sciences and Numerical Simulation celebrates the career of Professor Philip J. Morrison, whose research contributes to both mathematical physics and theoretical physics and is usually motivated by problems arising in plasma physics, geophysical fluid dynamics, or general fluid dynamics.

This special issue consists of papers by former students and long time collaborators. The broad range of topics reflects the diversity of his interests. It comes as no surprise that a significant number of the contributions originates from plasma physics, in particular in the Hamiltonian formulation of kinetic and fluid models, the numerical investigation of instabilities in plasmas, and the structure of magnetic field lines and equilibria. Related contributions deal also with the analysis of Hamiltonian systems and dynamical instabilities in fluid mechanics, and in particular geophysical fluids. Another group of contributions reflects Professor Morrison’s interests for lower- dimensional systems with a precise analysis of the dynamical structure of phase space and reduction methods with some emphasis on nontwist maps.

The NLDyn team announces the launching of its new website. The Nonlinear Dynamics team develops modeling, dynamical analysis and control methods in order to shed new light on a variety of physical processes, in particular, problems originating from classical mechanics. The team contributes theoretical works dealing with Hamiltonian systems, stochastic processes and dynamical system networks. It is inspired by mainly three specific applications : magnetized fusion plasma physics, atomic and molecular physics, and biophysics.

Link: http://nldyn.cpt.univ-mrs.fr

Please note that the Aims and Topics of interest of Communications in Nonlinear Science and Numerical Simulation (CNSNS) have been modified.

Aims:

The journal publishes original research findings on experimental observation, mathematical modeling, theoretical analysis and numerical simulation, for more accurate description, better prediction or novel application, of nonlinear phenomena in science and engineering. It offers a venue for researchers to make rapid exchange of ideas and techniques in nonlinear science and complexity.

The submission of manuscripts with cross-disciplinary approaches in nonlinear science and complexity is particularly encouraged

Topics of interest:

Nonlinear differential or delay equations, Lie group analysis and asymptotic methods, Discontinuous systems, Fractals, Chaos and encryption, Fractional calculus and dynamics, Nonlinear effects in quantum mechanics, Nonlinear stochastic processes, Experimental nonlinear science, Time-series and signal analysis, Computational methods and simulations in nonlinear science and engineering, Control of dynamical systems, Synchronization, Lyapunov analysis, High-dimensional chaos and turbulence, Chaos in Hamiltonian systems, Integrable systems and solitons, Collective behavior in many-body systems, Biological physics and networks, Nonlinear mechanical systems, Complex systems and complexity.

No length limitation for contributions is set, but only concisely written manuscripts are published. Brief papers are published on the basis of Rapid Communications. Discussions of previously published papers are welcome.

Reference: http://www.elsevier.com/wps/find/journaldescription.cws_home/622724/description

To submit a manuscript: http://ees.elsevier.com/cnsns/

Les prochaines journées DYCOEC auront lieu à Marseille.

Orateurs invités

• Phil Morrison (University of Texas at Austin)

• Hamid Kellay (Université de Bordeaux 1)

• Freddy Bouchet (ENS Lyon)

• Philippe Gendrih (CEA Cadarache)
  

Location

Amphi 5, CPT Marseille
Centre de Physique Théorique, UMR 6207
Campus de Luminy - Case 907
F-13288 Marseille cedex 09, France

More information: http://www.coria.fr/dycoec/spip.php?article136

The ability to generate complete, or almost complete, chaotic mixing is of great interest in numerous applications, particularly for microfluidics. For this purpose, we propose a strategy that allows us to quickly target the parameter values at which complete mixing occurs. The technique is applied to a time periodic, two-dimensional electro-osmotic flow with spatially and temporally varying Helmholtz-Smoluchowski slip boundary conditions. The strategy consists of following the linear stability of some key periodic pathlines in parameter space (i.e., amplitude and frequency of the forcing), particularly through the bifurcation points at which such pathlines become unstable.


Reference: R. Chabreyrie, C. Chandre, N. Aubry, Complete chaotic mixing in an electro-osmotic flow by destabilizing key periodic orbits, Physics of Fluids 23, 072002 (2011)

This one day symposium is devoted to laser-matter interactions with a particular emphasis on ultrafast processes as encountered in attosecond science. The speakers will present some of the most recent experimental results and their corresponding theoretical treatments (considering quantum, semi-classical or classical models). The targeted audience is atomic and molecular physicists, non-linear dynamists and mathematicians. This meeting is organ-ized by the Center for Theoretical Physics (CNRS/Aix Marseille Université, France).

Invited speakers
    Hans R. JAUSLIN (Université de Bourgogne, Dijon, France)
    Pascal SALIÈRES (CEA Saclay, France)
    Richard TAÏEB (Université Pierre et Marie Curie, Paris, France)
    Turgay UZER (Georgia Institute of Technology, USA)
    Olivier UTEZA (LP3, CNRS/Aix Marseille Université, France)

Location
    Amphi 5, CPT Marseille
    Centre de Physique Théorique,
    Campus de Luminy – case 907
    F-13288 Marseille cedex 09, France

Website: http://www.cpt.univ-mrs.fr/illuminyating

Poster: http://www.cpt.univ-mrs.fr/illuminyating/Poster_Web.pdf

Quand le champ laser joue à la pétanque...

More about it in La Lettre de l'Université de la Méditerranée 154, 28 (2010)

Reference: F. Mauger, C. Chandre, T. Uzer, Recollisions and correlated double ionization in circularly polarized light, Physical Review Letters 105, 083002 (2010)

Lorsqu’un atome est éclairé par une onde laser très intense, on peut observer une double ionisation corrélée, c’est à dire le départ simultané de deux électrons. Les expériences réalisées avec l’Hélium et la molécule d’Hydrogène ainsi que les interprétations théoriques de ce phénomène conduisaient à penser que seule une lumière polarisée linéairement produisait cette ionisation corrélée, en contradiction avec ce qui était observé avec le Magnésium où ce phénomène est aussi observé avec une polarisation circulaire. Des physiciens du Centre de Physique Théorique de Marseille (CPT – CNRS /Univ. Aix-Marseille II / Univ. Aix-Marseille I / Univ. de Toulon) en collaboration avec le Georgia Institute of Technology d’Atlanta ont permis de réconcilier ces résultats expérimentaux apparemment contradictoires en montrant comment un électron ionisé par le champ peut revenir vers le noyau pour ioniser d’autres électrons, même avec une polarisation circulaire.

Reference: http://www.cnrs.fr/inp/spip.php?article377