C. Labaune, F. Amiranoff, C. Chenais-popovics, J. Gauthier, M. Koenig, E. Dalimier, A. Migus, C. Sauteret
This paper reviews the highlights of the high intensity laser-plasma experiments achieved with the six-beam and the 100 TW LULI laser facilities, as well as the progress of the LULI 2000 project. This covers fields of laser fusion, equations of state, hgih energy particle emission, atomic physics, X-ray production and laser developments.
{"title":"High-intensity laser-plasma experiments at LULI","authors":"C. Labaune, F. Amiranoff, C. Chenais-popovics, J. Gauthier, M. Koenig, E. Dalimier, A. Migus, C. Sauteret","doi":"10.1117/12.536768","DOIUrl":"https://doi.org/10.1117/12.536768","url":null,"abstract":"This paper reviews the highlights of the high intensity laser-plasma experiments achieved with the six-beam and the 100 TW LULI laser facilities, as well as the progress of the LULI 2000 project. This covers fields of laser fusion, equations of state, hgih energy particle emission, atomic physics, X-ray production and laser developments.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"41 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":"125039005","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}
P. Naik, J. A. Chakera, V. Arora, N. K. Gupta, S. Sailaja, S. R. Kumbhare, P. Gupta, B. K. Godwal
In the indirect scheme of ICF, a high-Z ablator is used as the inside wall material of the hohlraum cavity. This choice is made because a high-Z plasma is an efficient x-ray convertor, and it offers a high opacity to radiation conduction into the cavity wall. Recently it had been shown that a mixture of two or more high-Z elements can provide a higher opacity than that of any single materials used, and optimum composition was predicted from computer simulations. It is expected that such a wall will provide maximum conversion of absorbed laser energy into soft x-ray radiation. In this paper, we present a comparative experimental study of soft x-ray emission from copper-gold mix-Z planar targets of different atomic compositions irradiated at a laser intensity of ~1013 W/cm2 (λ = 0.532μm). Spectral features of the soft x-ray radiation were recorded using a transmission grating spectrograph. Maximum enhancement in radiation intensity in the spectral region ~ 40 - 120 Å was observed for a mix-Z target of atomic composition of Cu 0.57 - Au 0.43. This is in broad agreement with theoretical results of opacity calculations performed for different atomic compositions using a screened hydrogenic average atom model.
{"title":"Dependence of soft x-ray conversion on atomic composition in laser-produced plasma of copper-gold mix-Z targets","authors":"P. Naik, J. A. Chakera, V. Arora, N. K. Gupta, S. Sailaja, S. R. Kumbhare, P. Gupta, B. K. Godwal","doi":"10.1117/12.534265","DOIUrl":"https://doi.org/10.1117/12.534265","url":null,"abstract":"In the indirect scheme of ICF, a high-Z ablator is used as the inside wall material of the hohlraum cavity. This choice is made because a high-Z plasma is an efficient x-ray convertor, and it offers a high opacity to radiation conduction into the cavity wall. Recently it had been shown that a mixture of two or more high-Z elements can provide a higher opacity than that of any single materials used, and optimum composition was predicted from computer simulations. It is expected that such a wall will provide maximum conversion of absorbed laser energy into soft x-ray radiation. In this paper, we present a comparative experimental study of soft x-ray emission from copper-gold mix-Z planar targets of different atomic compositions irradiated at a laser intensity of ~1013 W/cm2 (λ = 0.532μm). Spectral features of the soft x-ray radiation were recorded using a transmission grating spectrograph. Maximum enhancement in radiation intensity in the spectral region ~ 40 - 120 Å was observed for a mix-Z target of atomic composition of Cu 0.57 - Au 0.43. This is in broad agreement with theoretical results of opacity calculations performed for different atomic compositions using a screened hydrogenic average atom model.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"175 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":"131849476","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}
The hydrodynamic-radiation codes are used for a simulation of mean Rosseland and Planck opacities from different models similar to Hartree-Fock model, average ion model, detailed configuration accounting model, and so on. At present the necessity in such a data is high especially for plasma of mixture of ions. In this work we present the results on a comparison of mean opacities calculated by means of various codes and models. The calculations were carried out for the local thermodynamic equilibrium (LTE) plasmas of various chemical elements and mixtures. The models under consideration are the DESNA model and the THERMOS, JIMENA (analytical opacity formula), and the LEDCOP codes. The main results and conclusions about applicability of each of the approaches based on the comparison are presented for LTE plasma on Be, C, Al, SiO2. After verification, the results of the DESNA model calculations will be used to create the database on mean opacities in a broad range of plasma density and temperature for various materials, including the case of non-LTE plasma.
{"title":"Mean opacities of LTE plasmas: detailed configuration accounting versus other approaches","authors":"E. Ivanov, V. Rozanov, Galina A. Vergunova","doi":"10.1117/12.535961","DOIUrl":"https://doi.org/10.1117/12.535961","url":null,"abstract":"The hydrodynamic-radiation codes are used for a simulation of mean Rosseland and Planck opacities from different models similar to Hartree-Fock model, average ion model, detailed configuration accounting model, and so on. At present the necessity in such a data is high especially for plasma of mixture of ions. In this work we present the results on a comparison of mean opacities calculated by means of various codes and models. The calculations were carried out for the local thermodynamic equilibrium (LTE) plasmas of various chemical elements and mixtures. The models under consideration are the DESNA model and the THERMOS, JIMENA (analytical opacity formula), and the LEDCOP codes. The main results and conclusions about applicability of each of the approaches based on the comparison are presented for LTE plasma on Be, C, Al, SiO2. After verification, the results of the DESNA model calculations will be used to create the database on mean opacities in a broad range of plasma density and temperature for various materials, including the case of non-LTE plasma.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"59 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":"129780460","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}
R. Cook, M. Anthamatten, J. P. Armstrong, S. Letts, R. McEachern, B. Mcquillan, M. Takagi
The capsule targets for ignition experiments at the National Ignition Facility must meet very exacting requirements. Primary among them is an extremely high degree of symmetry at all length scales for the 2-mm-diameter 150-μm-walled capsule. At LLNL work is in progress to produce both polyimide and sputtered beryllium targets that meet these specifications. Both of these targets require a thin-walled spherical-shell plastic mandrel upon which the beryllium or polyimide ablator is deposited. In this paper we report on recent progress in developing NIF capsules that meet the demanding design requirements.
{"title":"Recent progress in the development of capsule targets for the National Ignition Facility","authors":"R. Cook, M. Anthamatten, J. P. Armstrong, S. Letts, R. McEachern, B. Mcquillan, M. Takagi","doi":"10.1117/12.537397","DOIUrl":"https://doi.org/10.1117/12.537397","url":null,"abstract":"The capsule targets for ignition experiments at the National Ignition Facility must meet very exacting requirements. Primary among them is an extremely high degree of symmetry at all length scales for the 2-mm-diameter 150-μm-walled capsule. At LLNL work is in progress to produce both polyimide and sputtered beryllium targets that meet these specifications. Both of these targets require a thin-walled spherical-shell plastic mandrel upon which the beryllium or polyimide ablator is deposited. In this paper we report on recent progress in developing NIF capsules that meet the demanding design requirements.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"153 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":"132379327","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}
Dynamics of the interactions of atoms with intense electromagnetic fields is considered. The theory of ionization and excitation of atoms by the short laser pulses is developed on the basis of the close-coupling approach for solving the time-dependent Schrodinger equation. Studies of the interactions of atoms with intense electromagnetic fields require the use all the continuous states of the system, without discretization of the continuum. The systematic investigations have been done in the case of femtosecond laser pulses with linear and circular polarization, for the different vlaues of the laser frequency, intensity and duration times. Interactions of the intermediate discrete states with the continuum (bound-free transitions) are found to be very important for structures of the energy spectra of the ejected electrons. It is shown that these bound-free transitions give the larger contributions than the rescattering process (free-free transitions) at the medium energies of the ejected electrons. The resonance and interference structures in populations of the discrete and continuum atomic states are displayed as functions of the laser pulse parameters in the case of the H-atoms and H-like ions.
{"title":"Ionization of atoms by short laser pulses: resonance and interference effects","authors":"A. Kondorskiy, L. Presnyakov","doi":"10.1117/12.536935","DOIUrl":"https://doi.org/10.1117/12.536935","url":null,"abstract":"Dynamics of the interactions of atoms with intense electromagnetic fields is considered. The theory of ionization and excitation of atoms by the short laser pulses is developed on the basis of the close-coupling approach for solving the time-dependent Schrodinger equation. Studies of the interactions of atoms with intense electromagnetic fields require the use all the continuous states of the system, without discretization of the continuum. The systematic investigations have been done in the case of femtosecond laser pulses with linear and circular polarization, for the different vlaues of the laser frequency, intensity and duration times. Interactions of the intermediate discrete states with the continuum (bound-free transitions) are found to be very important for structures of the energy spectra of the ejected electrons. It is shown that these bound-free transitions give the larger contributions than the rescattering process (free-free transitions) at the medium energies of the ejected electrons. The resonance and interference structures in populations of the discrete and continuum atomic states are displayed as functions of the laser pulse parameters in the case of the H-atoms and H-like ions.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"1 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":"125844611","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}
George M. Yankovskii, V. N. Kondrashov, Garry V. Anastasiev, O. L. Dedova, Ildar K. Fasakhov, Viktor M. Petryakov
We report on experiments conducted on the "Mishen" facility, in which thin burn-through and thick planar plastic foil targets were irradiated with a single 1.054 μm laser beam at intensities of ~5•1012 - 1014 W/cm2. Features of the stimulated Brillouin scattering along with the processes of resonance absorption, ion acoustic decay instability, and two- plasmon decay instability were studied. Interaction processes were identified from analysis of time behavior of backscattered light spectra at fundamental laser frequency, second and three-halves harmonics, as well as from transmitted light measurements. Experiments with obliquely irradiated targets of different types were also carried out and some interesting results were obtained. Comparison of the results with the published data is presented.
{"title":"Time-resolved spectroscopic study of laser-plasma interaction in experiments with burn-through targets","authors":"George M. Yankovskii, V. N. Kondrashov, Garry V. Anastasiev, O. L. Dedova, Ildar K. Fasakhov, Viktor M. Petryakov","doi":"10.1117/12.536572","DOIUrl":"https://doi.org/10.1117/12.536572","url":null,"abstract":"We report on experiments conducted on the \"Mishen\" facility, in which thin burn-through and thick planar plastic foil targets were irradiated with a single 1.054 μm laser beam at intensities of ~5•1012 - 1014 W/cm2. Features of the stimulated Brillouin scattering along with the processes of resonance absorption, ion acoustic decay instability, and two- plasmon decay instability were studied. Interaction processes were identified from analysis of time behavior of backscattered light spectra at fundamental laser frequency, second and three-halves harmonics, as well as from transmitted light measurements. Experiments with obliquely irradiated targets of different types were also carried out and some interesting results were obtained. Comparison of the results with the published data is presented.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"102 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":"124056098","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}
A. Iskakov, N. Demchenko, I. Lebo, V. Rozanov, V. Tishkin
Hot electrons may significantly influence interaction of ultra short laser pulses with solids. Accurate consideration of resonant absorption of laser energy and hot electrons generation at a critical surface was achieved through the developed physical and mathematical models. 2D ray tracing algorithm has been developed to simulate laser beam refraction and Bremsstrahlung absorption with allowance for non-linear influence of a strong electromagnetic field. Hot electrons transport was considered as a straight-line flows weakening by a friction force calculated in the approximation of the average state of ionization. Developed models were coupled with 2D Lagrangian gas dynamic code "ATLANT" that takes into account non-linear heat transport. The developed program has been applied to simulate irradiations of Al foils by picosecond laser double pulses. Hot electrons transport and heating resulted in thin foil explosions. The transition from exploding foil regime to the ablative one with foil thickening has been simulated and analyzed at various values of laser light intensity.
{"title":"2D Lagrangian code ATLANT-HE for simulation of laser-plasma interaction with allowance for hot electron generation and transport","authors":"A. Iskakov, N. Demchenko, I. Lebo, V. Rozanov, V. Tishkin","doi":"10.1117/12.536552","DOIUrl":"https://doi.org/10.1117/12.536552","url":null,"abstract":"Hot electrons may significantly influence interaction of ultra short laser pulses with solids. Accurate consideration of resonant absorption of laser energy and hot electrons generation at a critical surface was achieved through the developed physical and mathematical models. 2D ray tracing algorithm has been developed to simulate laser beam refraction and Bremsstrahlung absorption with allowance for non-linear influence of a strong electromagnetic field. Hot electrons transport was considered as a straight-line flows weakening by a friction force calculated in the approximation of the average state of ionization. Developed models were coupled with 2D Lagrangian gas dynamic code \"ATLANT\" that takes into account non-linear heat transport. The developed program has been applied to simulate irradiations of Al foils by picosecond laser double pulses. Hot electrons transport and heating resulted in thin foil explosions. The transition from exploding foil regime to the ablative one with foil thickening has been simulated and analyzed at various values of laser light intensity.","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":"129195379","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}
A treatment is given of harmonics generation resulting from nonlinear inverse bremsstrahlung in a plasma with an anisotropic bi-Maxwellian electron velocity distribution function. Inverse bremsstrahlung absorption of test electromagnetic wave is investigated as well.
{"title":"Harmonics generation in a plasma with anisotropic bi-Maxwellian distribution","authors":"G. Ferrante, M. Zarcone, S. A. Uryupin","doi":"10.1117/12.536943","DOIUrl":"https://doi.org/10.1117/12.536943","url":null,"abstract":"A treatment is given of harmonics generation resulting from nonlinear inverse bremsstrahlung in a plasma with an anisotropic bi-Maxwellian electron velocity distribution function. Inverse bremsstrahlung absorption of test electromagnetic wave is investigated as well.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"235 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":"120879794","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}
K. Makarov, D. D. Maluta, V. Roerich, Y. Satov, Y. Smakovskii, Andrei E. Stepanov
CO2 laser-produced plasma ion component parameters were studied experimentally and numerically for aluminum and lead targets at peak laser intensity of 4 x 1013 W cm-2 and FWHM pulse duration of 15 ns. Angular dependences of ion number density, average velocity, and its spread were measured for different charge states by time-of-flight method. Ion charge state distribution shows high-charge and low-charge state groups. Ions in these groups have different average expansion velocity and longitudinal velocity spread. Angular distribution of high charge states is narrower than that of the low-charge state ion group, maximum yield of low charge states occurs at some angle from normal. For Al target the results show similar trends as for Pb target, but simulations have indicated that the effect of laser ponderomotive force is more pronounced in this case.
在峰值激光强度为4 × 1013 W cm-2、FWHM脉冲持续时间为15 ns的条件下，对CO2激光产生的铝和铅靶的等离子体离子组分参数进行了实验和数值研究。用飞行时间法测量了不同电荷状态下离子数密度、平均速度及其扩散的角依赖性。离子的电荷态分布呈现出高电荷和低电荷的状态群。这些基团中的离子具有不同的平均膨胀速度和纵向速度扩散。高电荷态离子群的角分布比低电荷态离子群的窄，低电荷态的最大产率出现在偏离正态的一定角度。对于Al靶，结果与Pb靶的趋势相似，但模拟结果表明，在这种情况下，激光质动势的影响更为明显。
{"title":"Plasma heating by CO2-laser pulses for efficient multicharged ion generation","authors":"K. Makarov, D. D. Maluta, V. Roerich, Y. Satov, Y. Smakovskii, Andrei E. Stepanov","doi":"10.1117/12.536893","DOIUrl":"https://doi.org/10.1117/12.536893","url":null,"abstract":"CO2 laser-produced plasma ion component parameters were studied experimentally and numerically for aluminum and lead targets at peak laser intensity of 4 x 1013 W cm-2 and FWHM pulse duration of 15 ns. Angular dependences of ion number density, average velocity, and its spread were measured for different charge states by time-of-flight method. Ion charge state distribution shows high-charge and low-charge state groups. Ions in these groups have different average expansion velocity and longitudinal velocity spread. Angular distribution of high charge states is narrower than that of the low-charge state ion group, maximum yield of low charge states occurs at some angle from normal. For Al target the results show similar trends as for Pb target, but simulations have indicated that the effect of laser ponderomotive force is more pronounced in this case.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"1 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":"130795886","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}
Results are presented for a theoretical model, known as the ion model (IM), recently elaborated to calculate the radiative opacity of hot dense plasma. The density-functional theory is used to obtain the general set of self-consistent field equations that describe the state of the whole ensemble of plasma atoms and ions. Theoretical features of the Hartree-Fock-Slater model (HFS), the detail configuration accounting (DCA) and the ion model (IM), are considered. The (IM) model is used for optimal selections of compound chemical compositions for laser and heavy ion target designs.
{"title":"Theoretical models of hot dense plasmas for laser and heavy ion target designs","authors":"N. Orlov","doi":"10.1117/12.535980","DOIUrl":"https://doi.org/10.1117/12.535980","url":null,"abstract":"Results are presented for a theoretical model, known as the ion model (IM), recently elaborated to calculate the radiative opacity of hot dense plasma. The density-functional theory is used to obtain the general set of self-consistent field equations that describe the state of the whole ensemble of plasma atoms and ions. Theoretical features of the Hartree-Fock-Slater model (HFS), the detail configuration accounting (DCA) and the ion model (IM), are considered. The (IM) model is used for optimal selections of compound chemical compositions for laser and heavy ion target designs.","PeriodicalId":340981,"journal":{"name":"European Conference on Laser Interaction with Matter","volume":"21 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114034345","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：