The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
S Huller - One of the best experts on this subject based on the ideXlab platform.
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hydrodynamic simulation of subpicosecond Laser Interaction with solid density matter
Physical Review E, 2000Co-Authors: K Eidmann, J Meyertervehn, Theodor Schlegel, S HullerAbstract:The Interaction of ultrashort subpicosecond Laser pulses with initially cold and solid matter is investigated in a wide intensity range ${(10}^{11}$ to ${10}^{17} \mathrm{W}/{\mathrm{cm}}^{2})$ by means of the hydrodynamic code MULTI-FS, which is an extension of the long pulse version of MULTI [R. Ramis, R. Schmalz, and J. Meyer-ter-Vehn, Comput. Phys. Commun. 49, 475 (1988)]. Essential modifications for the treatment of ultrashort pulses are the solution of Maxwell's equations in a steep gradient plasma, consideration of the nonequilibrium between electrons and ions, and a model for the electrical and thermal conductivity covering the wide range from the solid state to the high temperature plasma. The simulations are compared with several absorption measurements performed with aluminum targets at normal and oblique incidence. Good agreement is obtained by an appropriate choice of the electron-ion energy exchange time (characterized by 10 to 20 ps in cold solid Al). In addition we discuss the intensity scaling of the temperature, of the pressure, and of the density, where the Laser energy is deposited in the expanding plasma, as well as the propagation of the heat wave and the shock wave into the solid. For Laser pulse durations $g~150 \mathrm{fs}$ considered in this paper the amount of isochorically heated matter at solid density is determined by the depth of the electron heat wave in the whole intensity range.
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hydrodynamic simulation of subpicosecond Laser Interaction with solid density matter
Physical Review E, 2000Co-Authors: K Eidmann, J Meyertervehn, Theodor Schlegel, S HullerAbstract:The Interaction of ultrashort subpicosecond Laser pulses with initially cold and solid matter is investigated in a wide intensity range (10(11) to 10(17) W/cm(2)) by means of the hydrodynamic code MULTI-FS, which is an extension of the long pulse version of MULTI [R. Ramis, R. Schmalz, and J. Meyer-ter-Vehn, Comput. Phys. Commun. 49, 475 (1988)]. Essential modifications for the treatment of ultrashort pulses are the solution of Maxwell's equations in a steep gradient plasma, consideration of the nonequilibrium between electrons and ions, and a model for the electrical and thermal conductivity covering the wide range from the solid state to the high temperature plasma. The simulations are compared with several absorption measurements performed with aluminum targets at normal and oblique incidence. Good agreement is obtained by an appropriate choice of the electron-ion energy exchange time (characterized by 10 to 20 ps in cold solid Al). In addition we discuss the intensity scaling of the temperature, of the pressure, and of the density, where the Laser energy is deposited in the expanding plasma, as well as the propagation of the heat wave and the shock wave into the solid. For Laser pulse durations >/=150 fs considered in this paper the amount of isochorically heated matter at solid density is determined by the depth of the electron heat wave in the whole intensity range.
Eugene G Gamaly - One of the best experts on this subject based on the ideXlab platform.
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physics of ultra short Laser Interaction with matter from phonon excitation to ultimate transformations
Progress in Quantum Electronics, 2013Co-Authors: Eugene G Gamaly, Andrei RodeAbstract:Abstract This review encompasses ultrafast Laser Interaction with matter in a broad range of intensities ~10 10 –10 15 W/cm 2 . We consider the material transformation processes successively with increase of the absorbed Laser intensity. We start with the subtle atomic displacements and excitation of phonons, and further analyze the phase transitions, ablation, transformation into plasma, and Interaction of Laser radiation with plasma up to the relativistic limit. The Laser pulse is considered as of ultra-short duration if it is shorter the time scale of major energy relaxation processes such as the electron-to-lattice energy transfer, heat diffusion, and hydrodynamic motion. We describe the material response from the first principles, aiming to establish analytical scaling relations, which link the Laser pulse characteristics with the properties of the material. Special section is dedicated to the possibility of creating super-high pressure and temperature with an ultrashort tabletop Laser. The influence of the Laser polarisation on the material ionisation is discussed. We consider theoretical and experimental aspects of a newly emerging topic of Interaction of the ultrashort vortex beams and sculptured beams possessing complicated spatial and temporal distribution of intensity, polarisation, and the geometrical Berry-phase with matter. In conclusion, we discuss future directions related to the Lasers and diagnostic tools on the attosecond time scale and with the photons energy in the x-ray range.
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the physics of ultra short Laser Interaction with solids at non relativistic intensities
Physics Reports, 2011Co-Authors: Eugene G GamalyAbstract:Abstract The Interaction of ultra-fast sub-picosecond Laser pulses with solids is a very broad area of research. The boundaries for research fields covered by this review are defined as follows. A Laser pulse in the context of the review is of ultra-short duration if the pulse is shorter than all major relaxation times. Such pulses excite only electrons, leaving the lattice cold for the time required for the transfer of the absorbed Laser energy from the heated electrons to the lattice. For this reason, any Laser-induced phase transformations occur in non-equilibrium conditions, making properties of the material drastically different from their equilibrium counterparts. We study Laser Interaction with matter in a broad range of intensities from those inducing subtle atomic excitations (∼1010 W/cm2) up to high intensity (∼1016 W/cm2), when solid is swiftly transformed into hot and dense plasma. The phenomena emerging in succession in response to increasing Laser intensity, namely, the excitations of coherent phonons, phase transitions, ablation, and transformation of material into plasma, are described in consecutive chapters. Two Interaction geometries are investigated: the Interaction of a Laser pulse with a surface, and confined Interaction when a Laser is focused inside a transparent solid. The highest intensity in all these studies is well below the relativistic limit. Therefore, super-intense Laser–matter Interactions are beyond the scope in this review. All phenomena involved in Laser–matter Interaction are considered from the first principles using explicit approximations, eventually aiming to establish the analytical scaling relations, which link the parameters of the Laser and the material and allow comparison with experiments. We compare theory to experiments in all intensity ranges. The applications of some studies are described in a separate chapter. The prospects of these studies are indicated in the conclusion.
A V Kim - One of the best experts on this subject based on the ideXlab platform.
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relativistic self induced transparency effect during ultraintense Laser Interaction with overdense plasmas why it occurs and its use for ultrashort electron bunch generation
Physics of Plasmas, 2010Co-Authors: V I Eremin, A V Korzhimanov, A V KimAbstract:A novel explanation of the relativistic self-induced transparency effect during superintense Laser Interaction with an overdense plasma is proposed. It was studied analytically and verified with direct modeling by particle-in-cell simulations. Based on this treatment, a method of ultrashort high-energy electron bunch generation with durations on a femtosecond time scale is also proposed and studied via numerical simulation.
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Plasma-field structures during relativistic Laser Interaction with overdense plasmas at finite electron temperatures
The European Physical Journal D, 2009Co-Authors: A V Korzhimanov, A V KimAbstract:A simple model taking into account the effect of electron temperature is derived to define the plasma-field structures which may arise during relativistically intense Laser Interaction with overdense plasmas. We show that there exist multilayer solutions with electron cavitation, allowing for both relativistic and ponderomotive nonlinearities. The influence of finite electron temperature on such structures is studied. Examples of these plasma-field structures for the cases of an infinite plasma and a plasma layer are presented.
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relativistic self induced transparency effect during ultraintense Laser Interaction with overdense plasmas why it occurs and its use for ultrashort electron bunch generation
arXiv: Plasma Physics, 2008Co-Authors: V I Eremin, A V Korzhimanov, A V KimAbstract:A novel explanation of the relativistic self-induced transparency effect during superintense Laser Interaction with an overdense plasma is proposed. We studied it analytically and verified with direct modeling by both PIC and kinetic equation simulations. Based on this treatment, a method of ultrashort high-energy electron bunch generation with durations on a few femtosecond time scale is also proposed and studied via numerical simulation
K Eidmann - One of the best experts on this subject based on the ideXlab platform.
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hydrodynamic simulation of subpicosecond Laser Interaction with solid density matter
Physical Review E, 2000Co-Authors: K Eidmann, J Meyertervehn, Theodor Schlegel, S HullerAbstract:The Interaction of ultrashort subpicosecond Laser pulses with initially cold and solid matter is investigated in a wide intensity range ${(10}^{11}$ to ${10}^{17} \mathrm{W}/{\mathrm{cm}}^{2})$ by means of the hydrodynamic code MULTI-FS, which is an extension of the long pulse version of MULTI [R. Ramis, R. Schmalz, and J. Meyer-ter-Vehn, Comput. Phys. Commun. 49, 475 (1988)]. Essential modifications for the treatment of ultrashort pulses are the solution of Maxwell's equations in a steep gradient plasma, consideration of the nonequilibrium between electrons and ions, and a model for the electrical and thermal conductivity covering the wide range from the solid state to the high temperature plasma. The simulations are compared with several absorption measurements performed with aluminum targets at normal and oblique incidence. Good agreement is obtained by an appropriate choice of the electron-ion energy exchange time (characterized by 10 to 20 ps in cold solid Al). In addition we discuss the intensity scaling of the temperature, of the pressure, and of the density, where the Laser energy is deposited in the expanding plasma, as well as the propagation of the heat wave and the shock wave into the solid. For Laser pulse durations $g~150 \mathrm{fs}$ considered in this paper the amount of isochorically heated matter at solid density is determined by the depth of the electron heat wave in the whole intensity range.
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hydrodynamic simulation of subpicosecond Laser Interaction with solid density matter
Physical Review E, 2000Co-Authors: K Eidmann, J Meyertervehn, Theodor Schlegel, S HullerAbstract:The Interaction of ultrashort subpicosecond Laser pulses with initially cold and solid matter is investigated in a wide intensity range (10(11) to 10(17) W/cm(2)) by means of the hydrodynamic code MULTI-FS, which is an extension of the long pulse version of MULTI [R. Ramis, R. Schmalz, and J. Meyer-ter-Vehn, Comput. Phys. Commun. 49, 475 (1988)]. Essential modifications for the treatment of ultrashort pulses are the solution of Maxwell's equations in a steep gradient plasma, consideration of the nonequilibrium between electrons and ions, and a model for the electrical and thermal conductivity covering the wide range from the solid state to the high temperature plasma. The simulations are compared with several absorption measurements performed with aluminum targets at normal and oblique incidence. Good agreement is obtained by an appropriate choice of the electron-ion energy exchange time (characterized by 10 to 20 ps in cold solid Al). In addition we discuss the intensity scaling of the temperature, of the pressure, and of the density, where the Laser energy is deposited in the expanding plasma, as well as the propagation of the heat wave and the shock wave into the solid. For Laser pulse durations >/=150 fs considered in this paper the amount of isochorically heated matter at solid density is determined by the depth of the electron heat wave in the whole intensity range.
Leonid V. Zhigilei - One of the best experts on this subject based on the ideXlab platform.
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The Role of Thermal Excitation of D Band Electrons in Ultrafast Laser Interaction With Noble (Cu) and Transition (Pt) Metals
First International Conference on Integration and Commercialization of Micro and Nanosystems Parts A and B, 2007Co-Authors: Zhibin Lin, Leonid V. ZhigileiAbstract:The temperature dependences of the electron heat capacity and electron-phonon coupling factor for noble (Cu) and transition (Pt) metals are investigated based on the electron density of states (DOS) obtained from ab initio electronic structure calculations. For Cu, d band electrons could be thermally excited when the electron temperature exceeds ∼3000 K, leading to a significant increase, up to an order of magnitude, in the electron-phonon coupling factor and strong enhancement of the electron heat capacity away from the linear dependence on the electron temperature, which is commonly used in most of the current computational and theoretical investigations of ultrafast Laser Interactions with metals. Opposite to the case in Cu, the thermal excitation of d band electrons in Pt leads to a monotonic decrease of the electron-phonon coupling factor and contributes to significant negative deviations of the electron heat capacity from the linear dependence in the range of electron temperatures that are typically realized in ultrafast Laser material processing applications. Strong and drastically different temperature dependences of the thermophysical properties predicted for Cu and Pt point to the importance of the electron DOS effects and the necessity of full consideration of thermal excitation of d band electrons for realistic modeling of short pulse Laser Interaction with noble and transition metals.Copyright © 2007 by ASME
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Numerical modeling of short pulse Laser Interaction with Au nanoparticle surrounded by water
Applied Surface Science, 2007Co-Authors: Alexey Volkov, Carlos A. Sevilla, Leonid V. ZhigileiAbstract:Abstract Short pulse Laser Interaction with a metal nanoparticle surrounded by water is investigated with a hydrodynamic computational model that includes a realistic equation of state for water and accounts for thermoelastic behavior and the kinetics of electron–phonon equilibration in the nanoparticle. Computational results suggest that, at Laser fluences close to the threshold for vapor bubble formation, the region of biological damage due to the Laser-induced thermal spike and the Interaction of the pressure wave with internal cell structures can be localized within short distances from the absorbing particle comparable to the particle diameter. This irradiation regime is suitable for targeted generation of thermal and mechanical damage at the sub-cellular level.
