Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Nonlinear optics (4)
- Solitons and modulation theory (2)
- Combustion theory (1)
- Electromagnetic cascading (1)
- Frequency-domain holography (1)
-
- Fused silica (1)
- LIQUID-CRYSTALS (1)
- Laser wakefield acceleration (1)
- Liquid crystal; Soliton; Soliton dipole; Nematicon; Modulation theory (1)
- Liquids and polymers Mathematical physics Computational physics Optics (1)
- Modified Korteweg-de Vries equation; Soliton; Undular bore; Modulation theory; Initial-boundary value problem (1)
- Multi-color laser beams in plasmas: All-optical control of nonlinear focusing and propagation (1)
- Nonlinear plasma wake (1)
- Nuclear activation (1)
- Particle-in-cell simulations (1)
- Plasma generation (1)
- Plasma-wave induced nonlinear refraction (1)
- Quantum optics and lasers (1)
- Reaction–diffusion–convection equations; Cubic autocatalysis; Applied electric field; Ionic migration; Singularity theory; Hopf bifurcations; Semi-analytical solutions (1)
- Relativistic self-focusing (1)
- Soft matter (1)
- Ultrafast optical diagnostics of plasma processes (numerical support of the experiment) (1)
- Ultrafast pulse propagation (1)
- Wakefield imaging (1)
- Publication
- File Type
Articles 1 - 18 of 18
Full-Text Articles in Physics
Material Damage From Ultrashort Bursts Of Light, Jeremy Gulley
Material Damage From Ultrashort Bursts Of Light, Jeremy Gulley
Jeremy R. Gulley
No abstract is currently available.
All-Optical Suppression Of Relativistic Self-Focusing Of Laser Beams In Plasmas, Serguei Y. Kalmykov, Sunghwan A. Yi, Gennady Shvets
All-Optical Suppression Of Relativistic Self-Focusing Of Laser Beams In Plasmas, Serguei Y. Kalmykov, Sunghwan A. Yi, Gennady Shvets
Serge Youri Kalmykov
It is demonstrated that a catastrophic relativistic self-focusing (RSF) of a high-power laser pulse can be prevented all-optically by a second, much weaker, copropagating pulse. RSF suppression occurs when the difference frequency of the pulses slightly exceeds the electron plasma frequency. The mutual defocusing is caused by the three-dimensional electron density perturbation driven by the laser beat wave slightly above the plasma resonance. A bi-envelope model describing the early stage of the mutual defocusing is derived and analyzed. Later stages, characterized by the presence of a strong electromagnetic cascade, are investigated numerically. Stable propagation of the laser pulse with weakly …
Homogeneous Dbd In N2: 1) Lif, Talif And Electrical Measurements, N. Gherardi, Et. Es-Sebbar, C. Sarra-Bourret, N. Naudé, F. Massines
Homogeneous Dbd In N2: 1) Lif, Talif And Electrical Measurements, N. Gherardi, Et. Es-Sebbar, C. Sarra-Bourret, N. Naudé, F. Massines
Dr. Et-touhami Es-sebbar
In this paper we compare two different discharges that can be obtained in a DBD configuration, that is to say the filamentary discharge (usual regime in atmospheric DBD) with the Atmospheric Pressure Townsend Discharge (APTD), which is a homogeneous regime obtained in nitrogen atmosphere. The aim is to help in the understanding of the processes which control the transition from one regime to the other. To do so, the discharge is characterized through electrical measurements, coupled with optical diagnostics among which Laser Induced Fluorescence (LIF) for radical density measurements. The influence of the addition of small quantities of additives on …
Active Species Generation Of Homogeneous Dbd In N2: Experiment And Modelling, N. Gherardi, Et. Es-Sebbar, C. Sarra-Bourret, N. Naudé, F. Massines, D. Tzyganov, P. Ségur, S. Pancheshnyi
Active Species Generation Of Homogeneous Dbd In N2: Experiment And Modelling, N. Gherardi, Et. Es-Sebbar, C. Sarra-Bourret, N. Naudé, F. Massines, D. Tzyganov, P. Ségur, S. Pancheshnyi
Dr. Et-touhami Es-sebbar
No abstract provided.
Surface Ion-Electron Recombination As The Main Source Of Atoms In Flowing N2 Dbd, D. Tsyganov, Et. Es-Sebbar, S. Pancheshnyi, N. Gherardi, P. Ségur, F. Massines
Surface Ion-Electron Recombination As The Main Source Of Atoms In Flowing N2 Dbd, D. Tsyganov, Et. Es-Sebbar, S. Pancheshnyi, N. Gherardi, P. Ségur, F. Massines
Dr. Et-touhami Es-sebbar
No abstract provided.
Talif Quantification Of Nitrogen Atoms Applied To Experimental Simulation Of Titan’S Atmosphere, Et. Es-Sebbar, Y. Benilan, E. Arzoumanian, M.-C. Gazeau
Talif Quantification Of Nitrogen Atoms Applied To Experimental Simulation Of Titan’S Atmosphere, Et. Es-Sebbar, Y. Benilan, E. Arzoumanian, M.-C. Gazeau
Dr. Et-touhami Es-sebbar
No abstract provided.
S.E.T.U.P., A New Program Of Representative Simulations Of Titan’S Atmosphere: Current Status, M-C. Gazeau, E. Arzoumanian, Y. Benilan, Et. Es-Sebbar, A. Jolly, S. Perrier, C. Romanzin
S.E.T.U.P., A New Program Of Representative Simulations Of Titan’S Atmosphere: Current Status, M-C. Gazeau, E. Arzoumanian, Y. Benilan, Et. Es-Sebbar, A. Jolly, S. Perrier, C. Romanzin
Dr. Et-touhami Es-sebbar
No abstract provided.
Comparison Of Townsend Dielectric Barrier Discharge In N2, N2/O2 And N2/N2o: Behavior And Density Of Radicals, F. Massines, Et. Es-Sebbar, N. Gherardi, N. Naudé, D. Tsyganov, P. Ségur, S. Pancheshnyi
Comparison Of Townsend Dielectric Barrier Discharge In N2, N2/O2 And N2/N2o: Behavior And Density Of Radicals, F. Massines, Et. Es-Sebbar, N. Gherardi, N. Naudé, D. Tsyganov, P. Ségur, S. Pancheshnyi
Dr. Et-touhami Es-sebbar
No abstract provided.
Simulation And Analysis Of Ultrafast-Laser-Pulse-Induced Plasma Generation In Fused Silica, Jeremy Gulley, Sebastian Winkler, W. M. Dennis
Simulation And Analysis Of Ultrafast-Laser-Pulse-Induced Plasma Generation In Fused Silica, Jeremy Gulley, Sebastian Winkler, W. M. Dennis
Jeremy R. Gulley
Recent experiments on optical damage by ultrashort laser pulses have demonstrated that the temporal pulse shape can dramatically influence plasma generation in fused silica. We use a modified 3+1D nonlinear Schrödinger equation for the pulse propagation coupled to a rate equation for the plasma density in the dielectric material to simulate pulse propagation and plasma formation in fused silica. We use these simulations to analyze the influence of pulse shape and beam geometry on the formation of the electron plasma and hence modification in the bulk material. In particular, we simulate the effect of pulses reconstructed from experimental data. It …
Studies Of Laser Wakefield Structures And Electron Acceleration In Underdense Plasmas, Anatoly Maksimchuk, Steven A. Reed, Stepan S. Bulanov, Vladimir Chvykov, Galina Kalintchenko, Takeshi Matsuoka, Christopher Mcguffey, Gerard Mourou, Natalia Naumova, John Nees, Pascal Rousseau, Victor Yanovsky, Karl Krushelnick, Nicholas H. Matlis, Serguei Y. Kalmykov, Gennady Shvets, Michael C. Downer, C. R. Vane, J. R. Beene, Daniel W. Stracener, David R. Schultz
Studies Of Laser Wakefield Structures And Electron Acceleration In Underdense Plasmas, Anatoly Maksimchuk, Steven A. Reed, Stepan S. Bulanov, Vladimir Chvykov, Galina Kalintchenko, Takeshi Matsuoka, Christopher Mcguffey, Gerard Mourou, Natalia Naumova, John Nees, Pascal Rousseau, Victor Yanovsky, Karl Krushelnick, Nicholas H. Matlis, Serguei Y. Kalmykov, Gennady Shvets, Michael C. Downer, C. R. Vane, J. R. Beene, Daniel W. Stracener, David R. Schultz
Serge Youri Kalmykov
Experiments on electron acceleration and optical diagnostics of laser wakes were performed on the HERCULES facility in a wide range of laser and plasma parameters. Using frequency domain holography we demonstrated single shot visualization of individual plasma waves, produced by 40 TW, 30 fs laser pulses focused to the intensity of 10^{19} W/cm^2 onto a supersonic He gas jet with plasma densities n_e ~ 10^{19} cm^{−3}. These holographic “snapshots” capture the variation in shape of the plasma wave with distance behind the driver, and resolve wave front curvature seen previously only in simulations. High-energy quasimonoenergetic electron beams were generated using …
Laboratory Experiments As Support To The Built Up Of Titan’S Theoretical Models And Interpretation Of Cassini-Huygens Data, M-C. Gazeau, Y Benilan, Et. Es-Sebbar, T. Ferradaz, E. Hébrard, A. Jolly, F. Raulin, C. Romanzin, J-C. Guillemin, C. Berteloite, A. Canosa, S. D. Le Picard, Ian R. Sims
Laboratory Experiments As Support To The Built Up Of Titan’S Theoretical Models And Interpretation Of Cassini-Huygens Data, M-C. Gazeau, Y Benilan, Et. Es-Sebbar, T. Ferradaz, E. Hébrard, A. Jolly, F. Raulin, C. Romanzin, J-C. Guillemin, C. Berteloite, A. Canosa, S. D. Le Picard, Ian R. Sims
Dr. Et-touhami Es-sebbar
No abstract provided.
Evolution Of Higher-Order Gray Hirota Solitary Waves, Tim Marchant
Evolution Of Higher-Order Gray Hirota Solitary Waves, Tim Marchant
Tim Marchant
The defocusing Hirota equation has dark and gray soliton solutions which are stable on a background of periodic waves of constant amplitude. In this paper, gray solitary wave evolution for a higher-order defocusing Hirota equation is examined. A direct analysis is used to identify families of higher-order gray Hirota solitary waves, which are embedded for certain parameter values. Soliton perturbation theory is used to detmine the detailed behavior of an evolving higher-order gray Hirota solitary wave. An integral expression for the first-order correction to the wave is found and analytical expressions for the steady-state and transient components of the solitary …
Mathematical Modelling Of Nematicons And Their Interactions, Prof. Tim Marchant
Mathematical Modelling Of Nematicons And Their Interactions, Prof. Tim Marchant
Tim Marchant
The mathematical modelling of guided wave (nematicon) propagation in liquid crystals is considered. Model equations are derived based on suitable trial functions in an averaged Lagrangian. These equations are used to model nematicon interactions.
Undular Bores And The Initial-Boundary Value Problem For The Modified Korteweg-De Vries Equation, Tim Marchant
Undular Bores And The Initial-Boundary Value Problem For The Modified Korteweg-De Vries Equation, Tim Marchant
Tim Marchant
Two types of analytical undular bore solutions, of the initial value problem for the modified Korteweg-de Vries (mKdV), are found. The first, an undular bore composed of cnoidal waves, is qualitatively similar to the bore found for the KdV equation, with solitons occurring at the leading edge and small amplitude linear waves occurring at the trailing edge. The second, a newly identified type of undular bore, consists of finite amplitude sinusiodal waves, which have a rational form. At the leading edge is the mKdV algebraic soliton, while, again, small amplitude linear waves occur at the trailing edge. The initial-boundary value …
Collisionless Shock Resolution In Nematic Liquid Crystals, Tim Marchant
Collisionless Shock Resolution In Nematic Liquid Crystals, Tim Marchant
Tim Marchant
The diffractive resolution on a collisionless shock formed along the spatial profile of a beam in a nematic liquid crystal is considered, this material being an example of a self-focusing, nonlocal medium. It is found that the shock is resolved through the formation of an undular bore structure which persists for experimentally relevant propagation distances due to nonlocality delaying the onset of modulational instability. Both 1+1 and 2+1 dimensional bores with circular symmetry are considered (termed line and circular bores, respectively). A semianalytical solution is developed for the line undular bore, approximating it as a train of uniform solitary waves. …
Semi-Analytical Solutions For A Gray-Scott Reaction-Diffusion Cell With An Applied Electric Field, Tim Marchant
Semi-Analytical Solutions For A Gray-Scott Reaction-Diffusion Cell With An Applied Electric Field, Tim Marchant
Tim Marchant
An ionic version of the Gray–Scott chemical reaction scheme is considered in a reaction–diffusion cell, with an applied electric field, which causes migration of the reactant and autocatalyst in a preferred direction. The Galerkin method is used to reduce the governing partial differential equations to an approximate model consisting of ordinary differential equations. This is accomplished by approximating the spatial structure of the reactant and autocatalyst concentrations. Bifurcation analysis of the semi-analytical model is performed by using singularity theory to analyse the static multiplicity and a stability analysis to determine the dynamic multiplicity. The application of the electric field causes …
Nonlocal Validity Of An Asymptotic One-Dimensional Nematicon Solution, Tim Marchant
Nonlocal Validity Of An Asymptotic One-Dimensional Nematicon Solution, Tim Marchant
Tim Marchant
The propagation of coherent, polarized light in a nematic liquid crystal, governed by the nematicon equations, is considered. It is found that in the special case of 1 + 1 dimensions and the highly nonlocal limit, the nematicon equations have an asymptotic bulk solitary wave solution, termed a nematicon, which is given in terms of Bessel functions. This asymptotic solution gives both the ground state and the symmetric and antisymmetric excited states, which have multiple peaks. Numerical simulations of nematicon evolution, for parameters corresponding to experimental scenarios, are presented. It is found, for experimentally reasonable parameter choices, that the validity …
Dipole Soliton Formation In A Nematic Liquid Crystal In The Non-Local Limit, Tim Marchant
Dipole Soliton Formation In A Nematic Liquid Crystal In The Non-Local Limit, Tim Marchant
Tim Marchant
The interaction of two symmetric solitary waves, termed nematicons, in a liquid crystal is considered in the limit of nonlocal response of the liquid crystal. This nonlocal limit is the applicable limit for most experimentally available liquid crystals. In this nonlocal limit, two separate cases for the initial separation of the nematicons are considered, these being large and small separation. Both spinning and nonspinning nematicons are considered. It is found that in the case of large initial separation, the nematicons can form a spinning or nonspinning bound state with a finite steady separation, this being called a nematicon dipole, when …