The Experts below are selected from a list of 28254 Experts worldwide ranked by ideXlab platform
C. Ren - One of the best experts on this subject based on the ideXlab platform.
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simulation of stimulated brillouin scattering and stimulated raman scattering in shock ignition
Physics of Plasmas, 2016Co-Authors: Liang Hao, R Yan, W D Liu, C. RenAbstract:We study stimulated Brillouin scattering (SBS) and stimulated Raman scattering (SRS) in shock ignition by comparing fluid and particle-in-cell (PIC) simulations. Under typical parameters for the OMEGA experiments [Theobald et al., Phys. Plasmas 19, 102706 (2012)], a series of 1D fluid simulations with laser intensities ranging between 2 × 1015 and 2 × 1016 W/cm2 finds that SBS is the dominant instability, which increases significantly with the Incident Intensity. Strong pump depletion caused by SBS and SRS limits the transmitted Intensity at the 0.17nc to be less than 3.5 × 1015 W/cm2. The PIC simulations show similar physics but with higher saturation levels for SBS and SRS convective modes and stronger pump depletion due to higher seed levels for the electromagnetic fields in PIC codes. Plasma flow profiles are found to be important in proper modeling of SBS and limiting its reflectivity in both the fluid and PIC simulations.
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simulation of stimulated brillouin scattering and stimulated raman scattering in shock ignition
arXiv: Plasma Physics, 2016Co-Authors: Liang Hao, R Yan, W D Liu, C. RenAbstract:We study stimulated Brillouin scattering (SBS) and stimulated Raman scattering (SRS) in shock ignition by comparing fluid and PIC simulations. Under typical parameters for the OMEGA experiments [Theobald \emph{et al}., Phys. Plasmas \textbf{19}, 102706 (2012)], a series of 1D fluid simulations with laser intensities ranging between 2$\times$10$^{15}$ and 2$\times$10$^{16}$ W/cm$^2$ finds that SBS is the dominant instability, which increases significantly with the Incident Intensity. Strong pump depletion caused by SBS and SRS limits the transmitted Intensity at the 0.17n$_c$ to be less than 3.5$\times$10$^{15}$ W/cm$^2$. The PIC simulations show similar physics but with higher saturation levels for SBS and SRS convective modes and stronger pump depletion due to higher seed levels for the electromagnetic fields in PIC codes. Plasma flow profiles are found to be important in proper modeling of SBS and limiting its reflectivity in both the fluid and PIC simulations.
Maryse Muller - One of the best experts on this subject based on the ideXlab platform.
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measurement of laser absorptivity for operating parameters characteristic of laser drilling regime
Journal of Physics D, 2008Co-Authors: Matthieu Schneider, Laurent Berthe, Rémy Fabbro, Maryse MullerAbstract:Laser drilling in the percussion regime is commonly used in the aircraft industry to drill sub-millimetre holes in metallic targets. Characteristic laser intensities in the range of 10 MW cm −2 are typically employed for drilling metallic targets. With these intensities the temperature of the irradiated matter is above the vaporization temperature and the drilling process is led by hydrodynamic effects. Although the main physical processes involved are identified, this process is not correctly understood or completely controlled. A major characteristic coefficient of laser–matter interaction for this regime, which is the absorptivity of the laser on the irradiated surface, is still unknown, because of the perturbing effects due to laser beam geometrical trapping inside the drilled hole. So, by using time resolved experiments, this study deals with the direct measurement of the variation of the intrinsic absorption of aluminium, nickel and steel materials, as a function of the Incident laser Intensity up to 20 MW cm −2 . We observe that for this Incident Intensity, the absorptivity can reach up to 80%. This very high and unexpected value is discussed by considering the microscopic behaviour of the heated matter near the vapour–liquid interface that undergoes possible Rayleigh–Taylor instability or volume absorption. (Some figures in this article are in colour only in the electronic version)
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Measurement of laser absorptivity for operating parameters characteristic of laser drilling regime
Journal of Physics D: Applied Physics, 2008Co-Authors: Matthieu Schneider, Laurent Berthe, Rémy Fabbro, Maryse MullerAbstract:Laser drilling in the percussion regime is commonly used in the aircraft industry to drill sub-millimetre holes in metallic targets. Characteristic laser intensities in the range of 10 MW cm−2 are typically employed for drilling metallic targets. With these intensities the temperature of the irradiated matter is above the vaporization temperature and the drilling process is led by hydrodynamic effects. Although the main physical processes involved are identified, this process is not correctly understood or completely controlled. A major characteristic coefficient of laser-matter interaction for this regime, which is the absorptivity of the laser on the irradiated surface, is still unknown, because of the perturbing effects due to laser beam geometrical trapping inside the drilled hole. So, by using time resolved experiments, this study deals with the direct measurement of the variation of the intrinsic absorption of aluminium, nickel and steel materials, as a function of the Incident laser Intensity up to 20 MW cm−2. We observe that for this Incident Intensity, the absorptivity can reach up to 80%. This very high and unexpected value is discussed by considering the microscopic behaviour of the heated matter near the vapour-liquid interface that undergoes possible Rayleigh-Taylor instability or volume absorption
Liang Hao - One of the best experts on this subject based on the ideXlab platform.
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simulation of stimulated brillouin scattering and stimulated raman scattering in shock ignition
Physics of Plasmas, 2016Co-Authors: Liang Hao, R Yan, W D Liu, C. RenAbstract:We study stimulated Brillouin scattering (SBS) and stimulated Raman scattering (SRS) in shock ignition by comparing fluid and particle-in-cell (PIC) simulations. Under typical parameters for the OMEGA experiments [Theobald et al., Phys. Plasmas 19, 102706 (2012)], a series of 1D fluid simulations with laser intensities ranging between 2 × 1015 and 2 × 1016 W/cm2 finds that SBS is the dominant instability, which increases significantly with the Incident Intensity. Strong pump depletion caused by SBS and SRS limits the transmitted Intensity at the 0.17nc to be less than 3.5 × 1015 W/cm2. The PIC simulations show similar physics but with higher saturation levels for SBS and SRS convective modes and stronger pump depletion due to higher seed levels for the electromagnetic fields in PIC codes. Plasma flow profiles are found to be important in proper modeling of SBS and limiting its reflectivity in both the fluid and PIC simulations.
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simulation of stimulated brillouin scattering and stimulated raman scattering in shock ignition
arXiv: Plasma Physics, 2016Co-Authors: Liang Hao, R Yan, W D Liu, C. RenAbstract:We study stimulated Brillouin scattering (SBS) and stimulated Raman scattering (SRS) in shock ignition by comparing fluid and PIC simulations. Under typical parameters for the OMEGA experiments [Theobald \emph{et al}., Phys. Plasmas \textbf{19}, 102706 (2012)], a series of 1D fluid simulations with laser intensities ranging between 2$\times$10$^{15}$ and 2$\times$10$^{16}$ W/cm$^2$ finds that SBS is the dominant instability, which increases significantly with the Incident Intensity. Strong pump depletion caused by SBS and SRS limits the transmitted Intensity at the 0.17n$_c$ to be less than 3.5$\times$10$^{15}$ W/cm$^2$. The PIC simulations show similar physics but with higher saturation levels for SBS and SRS convective modes and stronger pump depletion due to higher seed levels for the electromagnetic fields in PIC codes. Plasma flow profiles are found to be important in proper modeling of SBS and limiting its reflectivity in both the fluid and PIC simulations.
Aephraim M. Steinberg - One of the best experts on this subject based on the ideXlab platform.
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observation of the nonlinear phase shift due to single post selected photons
Nature Physics, 2015Co-Authors: Amir Feizpour, Greg Dmochowski, Matin Hallaji, Aephraim M. SteinbergAbstract:Using post-selection and electromagnetically induced transparency in a cold atomic gas it is now possible to generate a strong nonlinear interaction between two optical beams, bringing nonlinear optics into the quantum regime. Over the past years, much effort has gone towards generating interactions between two optical beams so strong that they could be observed at the level of individual photons1,2,3. Interactions this strong, beyond opening up a new regime in optics4, could lead to technologies such as all-optical quantum information processing5,6. However, the extreme weakness of photon–photon scattering has hindered any attempt to observe such interactions at the level of single particles. Here we present an implementation of a strong optical nonlinearity using electromagnetically induced transparency7, and a direct measurement of the resulting nonlinear phase shift for single post-selected photons. We show that the observed phase shift depends not only on the Incident Intensity of the (coherent-state) input signal, but also in a discrete fashion on whether 0 or 1 photons are detected at the output. We believe that this constitutes the first direct measurement of the cross-phase shift due to single photons, whose presence or absence is established based on a discrete detection event. It opens a door to future studies of nonlinear optics in the quantum regime, and potential applications in areas such as quantum information processing.
Matthieu Schneider - One of the best experts on this subject based on the ideXlab platform.
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measurement of laser absorptivity for operating parameters characteristic of laser drilling regime
Journal of Physics D, 2008Co-Authors: Matthieu Schneider, Laurent Berthe, Rémy Fabbro, Maryse MullerAbstract:Laser drilling in the percussion regime is commonly used in the aircraft industry to drill sub-millimetre holes in metallic targets. Characteristic laser intensities in the range of 10 MW cm −2 are typically employed for drilling metallic targets. With these intensities the temperature of the irradiated matter is above the vaporization temperature and the drilling process is led by hydrodynamic effects. Although the main physical processes involved are identified, this process is not correctly understood or completely controlled. A major characteristic coefficient of laser–matter interaction for this regime, which is the absorptivity of the laser on the irradiated surface, is still unknown, because of the perturbing effects due to laser beam geometrical trapping inside the drilled hole. So, by using time resolved experiments, this study deals with the direct measurement of the variation of the intrinsic absorption of aluminium, nickel and steel materials, as a function of the Incident laser Intensity up to 20 MW cm −2 . We observe that for this Incident Intensity, the absorptivity can reach up to 80%. This very high and unexpected value is discussed by considering the microscopic behaviour of the heated matter near the vapour–liquid interface that undergoes possible Rayleigh–Taylor instability or volume absorption. (Some figures in this article are in colour only in the electronic version)
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Measurement of laser absorptivity for operating parameters characteristic of laser drilling regime
Journal of Physics D: Applied Physics, 2008Co-Authors: Matthieu Schneider, Laurent Berthe, Rémy Fabbro, Maryse MullerAbstract:Laser drilling in the percussion regime is commonly used in the aircraft industry to drill sub-millimetre holes in metallic targets. Characteristic laser intensities in the range of 10 MW cm−2 are typically employed for drilling metallic targets. With these intensities the temperature of the irradiated matter is above the vaporization temperature and the drilling process is led by hydrodynamic effects. Although the main physical processes involved are identified, this process is not correctly understood or completely controlled. A major characteristic coefficient of laser-matter interaction for this regime, which is the absorptivity of the laser on the irradiated surface, is still unknown, because of the perturbing effects due to laser beam geometrical trapping inside the drilled hole. So, by using time resolved experiments, this study deals with the direct measurement of the variation of the intrinsic absorption of aluminium, nickel and steel materials, as a function of the Incident laser Intensity up to 20 MW cm−2. We observe that for this Incident Intensity, the absorptivity can reach up to 80%. This very high and unexpected value is discussed by considering the microscopic behaviour of the heated matter near the vapour-liquid interface that undergoes possible Rayleigh-Taylor instability or volume absorption
