European Conference on Laser Interaction with Matter最新文献

{"title":"Energy efficiency of laser greenhouse target for a small number of irradiating beams","authors":"R. Stepanov, A. Caruso, N. Demchenko, S. Gus'kov, V. Rozanov, C. Strangio, N. Zmitrenko","doi":"10.1117/12.536752","DOIUrl":"https://doi.org/10.1117/12.536752","url":null,"abstract":"Targets of the \"Laser Greenhouse\" (GH) type are very promising ones for direct laser compression. The key feature of this type of targets is the presence of a layer of low-density volume structured medium, which surrounds a thermonuclear cell and acts as the laser radiation absorber. Some methods to achieve highly symmetrical compression of these targets by small (e.g. two) number of laser beams (or beam clusters) have been presented earlier. Simulations of compression of targets for total laser pulse energy of 100 kJ and 2.1 MJ have proved, that this type of targets allows one to achieve combustion and effective burn. In the paper we introduce the results of 2D simulations of some processes, which are specific to this design of targets. The attention is paid to the problem of symmetry of compression. We also have performed calculations of neutron yield of the target designed for compression by two beams with full energy of 2.6 kJ, and series of 2D simulations to model some microscopic processes in the absorber. The experiments on compression of the targets at energy level of 2.6 kJ can be performed on a number of present laser installations.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122300114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Front-end system of the Luch facility","authors":"N. Rukavishnikov, A. Savkin, O. A. Sharov, S. Sukharev, B. G. Zimalin","doi":"10.1117/12.537387","DOIUrl":"https://doi.org/10.1117/12.537387","url":null,"abstract":"In 2001 a primary start-up of one channel of the four-channel \"Luch\" facility, a module of 128-channel facility has been realized. The facility intend for inertial confinement fusion. This paper presents the main results of work on creation and start-up of front-end system (FES) of \"Luch\" facility. The pulse of radiation with the energy up to 3 J and regulated pulse shape 1 - 10 ns in a square (36 x 36 mm2) beam was obtained at the output of FES.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"5228 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129303168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laser wake field acceleration in bubble regime: quasi-monoenergetic electron bunches and flashes of synchrotron radiation","authors":"A. Pukhov, S. Kiselev, I. Kostyukov, J. Meyer-ter-Vehn","doi":"10.1117/12.536784","DOIUrl":"https://doi.org/10.1117/12.536784","url":null,"abstract":"Using our 3D PIC code VLPL (Virtual Laser-Plasma Laboratory) we study Laser-Wake Field Acceleration (LWFA) of electrons by laser pulses shorter than or comparable with the plasma wavelength. When driven into the highly non-linear wave breaking regime the plasma wave mutates to a solitary bubble that generates ultra-short dense bunches of electrons with quasi-monoenergetic energy spectra. The electron bunches may have density high enough to forward-scatter the tail of the laser pulse. The forward scattering results in blue shift of the laser pulse after interaction. The energetic electrons make betatron oscillations in transverse fields of the plasma wave and emit hard X- and γ-rays. We show that an extremely bright source of GeV γ-quanta can be built due to the combination of an external electron beam and the laser wake field. The GeV γ-source can be particularly used as an efficient plant for positron production.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121545386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical modeling of laser target experiments at GARPUN and PICO installations","authors":"I. Lebo, A. Iskakov, Y. Mikhailov, V. Rozanov, A. N. Starodub, G. Sklizkov, V. Tishkin, V. Zvorykin","doi":"10.1117/12.536561","DOIUrl":"https://doi.org/10.1117/12.536561","url":null,"abstract":"The 2D codes \"ATLANT-C\" (Lagrangian coordiantes) and \"NUTCY\" (Euler coordinates) have been used for the modeling of experiments performed at laser installations \"GARPUN\" (KrF-laser with pulse energy about 100 J and duration of 100 ns) and \"PICO\" (Nd-laser with pulse energy of 30 J and duration of 3 ns). Both laser installations are located at Lebedev Physical Institute, Moscow, Russia.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"2016 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127478413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and numerical studies of the structure of cluster targets for femtosecond laser pulses","authors":"A. Boldarev, V. Gasilov, F. Blasco, F. Dorchies, C. Stenz","doi":"10.1117/12.543122","DOIUrl":"https://doi.org/10.1117/12.543122","url":null,"abstract":"A mathematical model of clusters forming in gas jets is proposed. This model concerns with the representation of the clusters by the moments of the distribution function of the clusters with respect to the radius. This model uses the kinetic theory of phase transitions presented by Frenkel for the kinetic of the clusters formation. The numerical results obtained with the help of this model are compared with the direct experimental measurements based on Mach-Zehnder interferometry and Rayleigh scattering.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"188 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132848401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"X-ray line emission from H-like and He-like ions in magnesium plasma produced by multi-picosecond laser pulses","authors":"P. Naik, V. Arora, R. Khan, P. Gupta","doi":"10.1117/12.536940","DOIUrl":"https://doi.org/10.1117/12.536940","url":null,"abstract":"We report a spectroscopic study of x-ray line emission from a magnesium plasma produced by Nd:glass laser pulses of 30 ps (FWHM) duration at a laser intensity of ~ 3 x 1014 Wcm-2. High-resolution x-ray line spectrum was recorded using a crystal spectrograph. Measurements of continuum radiation intensity were also performed for different x-ray filter cutoff energies. A peak electron temperature of ~ 2.4 keV derived from these measurements is in agreement with that calculated from an analytical model describing laser plasma heating in the short pulse regime. The intensity ratio of MgXII 1s-2p, λ = 8.42 Å and MgXI 1s2-1s2p, λ = 9.17 Å is observed to be much smaller than that calculated from the spectroscopic code RATION. Analytical estimates of ionization equilibrium time for different ionization states in the heated plasma as well as during its expansion using a simple hydrodynamic model can explain this behavior.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133894704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transient dielectric function of gallium undergoing order-disorder phase transition induced by femtosecond laser pulses","authors":"E. Gamaly, O. Uteza, A. Rode, M. Samoć, B. Luther-Davies","doi":"10.1117/12.537284","DOIUrl":"https://doi.org/10.1117/12.537284","url":null,"abstract":"The reflectivity of Gallium films excited by femtosecond laser can be raised from ~55% to up to ~85% on a picosecond time-scale. Temporal behavior of the reflectivity exhibits three clearly distinguished stages: an initial 2 - 4 ps sharp rise, a relatively slow increase to a maximum value in a few 100 ps, and afterwards a long slope in ~ (0.1 - 1) μs to the original value. In this paper we present reflectivity measurements in a pump-probe scheme with one pump and two identical simultaneous femtosecond probes set at two different angles, which completely determines the real and imaginary parts of the dielectric function with time resolution ~ 200 fs. The analysis of the experimental data uncovered a number of new phenomena: (1) the energy density threshold to initiate phase transition is several times lower than the equilibrium enthalpy of melting; (2) the initial 2 - 4 ps rise of reflectivity relates to the transformation to a new phase in the absence of energy loss due to cooling. The second, slower stage (~100 ps) relates to a heat conduction dominated process; (3) the rate of the reflectivity change strongly increases with the increase of the pump laser intensity; (4) the volume fraction of the new phase reaches only 60% even with the deposited energy exceeds more than two times the equilibrium enthalpy of melting; (5) the electron-to-lattice coupling rate is a transient non-linear function of temperature that is drastically different from the equilibrium conditions. The results suggest a mechanism to control of the reflectivity switching, and thus the duty cycle of the reversible phase transition (crystal-metal-crystal), through an optimal combination of the laser parameters, target and substrate material. As a result, new all-optical switching devices with ps-range switching time could be designed utilizing the nonlinear dielectric properties of the non-equilibrium solid-state plasma.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121961091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Observation of hydrodynamic effects in laser-irradiated multifoil targets","authors":"V. N. Kondrashov, N. Demchenko, Valeriy V. Gavrilov, N. G. Kovalskiy, Viktor M. Petryakov, George M. Yankovskii","doi":"10.1117/12.536478","DOIUrl":"https://doi.org/10.1117/12.536478","url":null,"abstract":"To experimentally model laser-plasma interaction in low-density porous media, we have started irradiating plastic multifoil targets with a single 1.054 μm laser beam at approximately 1014 W/cm2 at the \"Mishen\" facility. A first foil directly irradiated was thin enough to burn through and rapidly become underdense. Acceleration and expansion of the high-temperature plasma inward the target, its stagnation under impacts on successive foils, and reverse shock propagation into the plasma corona occur during the laser pulse. Hydrodynamics of plasma in multifoil targets was studied by analyzing the spectral shifts of backscattered laser light and its harmonics. The experimental data interpretation employs results of the one-dimensional hydrodynamic simulation.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131183409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects connected to the interaction of microwave-frequency-modulated laser radiation with plasma","authors":"V. V. Rudenko, N. S. Zakharov","doi":"10.1117/12.536892","DOIUrl":"https://doi.org/10.1117/12.536892","url":null,"abstract":"The oscillations of the gas dynamic and electrodynamics parameters of plasma generated under the action of a powerful UHF-modulated laser radiation are investigated theoretically when the characteristic laser radiation intensity modulation time is significantly less than the characteristic time of variation of the gas dynamic parameters of the plasma. It is demonstrated that the values of the parameters may be found using the averaging method and represented in the form of the sum of two parts, of which one part is the solution in the absence of modulation, and the other part describes small-scale oscillations about this solution.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132043688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electron acceleration in high-amplitude surface plasma waves excited by ultrashort laser","authors":"J. Kupersztych, M. Raynaud, C. Riconda","doi":"10.1117/12.536910","DOIUrl":"https://doi.org/10.1117/12.536910","url":null,"abstract":"We have investigated a new mechanism for creation of relativistic electrons via the acceleration by the resonant field of laser excited surface plasma waves in sharp-edged overdense plasmas. This mechanism consists in a generalization to high-intensity laser fields of an effect recently observed in the context of short-pulse laser metal interaction. As it is well known, a p-polarized laser impinging onto a structured metal surface creates a plasma during the rise time of the laser pulse, which can reach temperatures of several hundreds of eV. If the pulse duration (<~ 100 fs) is such that the interaction of the electrons with the surface plasma wave occurs before the hydrodynamic expansion has time to smooth the plasma density sharp edge, the conditions for resonant excitation of surface plasma waves by the laser can be fulfilled. We show that in this case the strongly inhomogeneous enhanced electric field located near the plasma surface may accelerate the electrons toward the vacuum, the efficiency of this mechanism depending on the ratio RL between two characteristic lengths: the extension length of the surface wave field in the vacuum and the typical distance covered by the particles in the high-frequency high-amplitude field. We find an optimum regime for RL of the order of unity, in which case the electrons can be accelerated up to a momentum of the order of magnitude of the high-frequency momentum posc in the enhanced field of the surface plasma wave. The results of a 1D relativistic test-particle simulation modeling the interaction of the electrons with the plasma wave field are presented. In particular, we show that electron energies of some MeV may be reached for laser intensities of the order of 1018W/cm2. The resulting electron energy distribution function is numerically calculated for the optimum case. The spectrum shows a well-defined peaked structure due to the dependence on the phase of the plasma wave field experienced by the accelerated electrons. This study suggests a novel possibility of high-current energetic pulsed electron sources.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"231 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115582269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}