Three-dimensional symmetry analysis of a direct-drive irradiation scheme for the laser megajoule facility

Ramis, R.; Temporal, M.; Canaud, B.; Brandon, V.

doi:10.1063/1.4893311

Cited by 12 publications

(10 citation statements)

References 44 publications

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“…Assuming a uniform intensity profile of the laser beams, calculations show that the irradiation uniformity of the target surface outside the cone is r ¼ 5:8% when the laser beams remain at their original positions, which is higher than 1% that commonly accepted as the typical allowed asymmetry for ICF capsules. 11,23,29 Though fast ignition relaxes the requirements on the symmetry of the implosion, it is still necessary to keep highly uniform irradiation to achieve high density and areal density. 10 In the following, we aim to reduce the RMS to about 1%, which is sufficient for fast ignition.…”

Section: A Irradiation Uniformity Of the Cone-in-shell Targetmentioning

confidence: 99%

“…To employ these ID configurations for DD fusion, some methods have been proposed, for instance, the Polar Direct Drive (PDD) technique 21 that displaces the laser beams toward the equatorial plane by a distance d to provide a more uniform irradiation on the capsule. However, most of these researches [22][23][24][25][26] are based on spherical capsule which is for conventional central hot-spot ignition or shock ignition, and there is little report about optimization of irradiation uniformity of cone-in-shell target in fast ignition. In Ref.…”

Section: Introductionmentioning

confidence: 99%

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Optimizing design of irradiation uniformity of direct drive cone-in-shell target for fast ignition

et al. 2015

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The irradiation uniformity of a cone-in-shell target directly driven by laser beams has been considered. First, a model is established to include the influence of the cone on laser beam propagation. Then, the irradiation uniformity on the target surface outside the cone during the initial imprinting phase is analyzed, and highly uniform irradiation on the target surface outside the cone is achieved by optimizing the intensity distribution within laser beams, as well as the polar direct drive displacement. As an illustrative example, direct drive irradiation uniformity of a typical cone-in-shell target is improved for Shenguang III laser facility, the illumination non-uniformity is reduced from 5.8% to 1.1%. Irradiation on the cone surface outside the target is also analyzed, and it is found that for the laser-target configuration considered in this work, a gold cone thicker than 50μm is needed to avoid shock breakout. Moreover, sensitivity to beam uncertainties (power imbalance and pointing error) is analyzed, indicating that this scheme can tolerate a certain amount of beam errors.

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Section: A Irradiation Uniformity Of the Cone-in-shell Targetmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Optimizing design of irradiation uniformity of direct drive cone-in-shell target for fast ignition

et al. 2015

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“…Recently, using the 3D version of the MULTI [55] code, the uniformity of the irradiation provided by the LMJ facility has been analysed. Here, we report only on a few results of a much larger and detailed analysis [86] . The 3D version of the MULTI code assumes a non-structured Lagrangian mesh (tetrahedral elements) and accounts for flux-limited (10%) thermal heat conduction, tabulated equations of state, and a 3D ray-tracing package for the laser energy deposition.…”

Section: D Hydrodynamic Simulationsmentioning

confidence: 99%

“…These conclusions hold when spots of adjacent beams have enough overlapping, provided that uncertainties in beam power balance and pointing accuracy can be neglected. It must be mentioned that, for configurations where the beam size has been reduced (FWHM ≈ 1000 µm), 3D effects occur, and azimuthal distortions can becomes significant even for N ≈ 5 [86] .…”

Section: D Hydrodynamic Simulationsmentioning

confidence: 99%

Irradiation uniformity at the Laser MegaJoule facility in the context of the shock ignition scheme

Temporal

Canaud

Garbett

et al. 2014

High Pow Laser Sci Eng

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The use of the Laser MegaJoule facility within the shock ignition scheme has been considered. In the first part of the study, one-dimensional hydrodynamic calculations were performed for an inertial confinement fusion capsule in the context of the shock ignition scheme providing the energy gain and an estimation of the increase of the peak power due to the reduction of the photon penetration expected during the high-intensity spike pulse. In the second part, we considered a Laser MegaJoule configuration consisting of 176 laser beams that have been grouped providing two different irradiation schemes. In this configuration the maximum available energy and power are 1.3 MJ and 440 TW. Optimization of the laser-capsule parameters that minimize the irradiation non-uniformity during the first few ns of the foot pulse has been performed. The calculations take into account the specific elliptical laser intensity profile provided at the Laser MegaJoule and the expected beam uncertainties. A significant improvement of the illumination uniformity provided by the polar direct drive technique has been demonstrated. Three-dimensional hydrodynamic calculations have been performed in order to analyse the magnitude of the azimuthal component of the irradiation that is neglected in twodimensional hydrodynamic simulations.

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“…1. The warm dense matter generation by a fs laser (heater) is simulated by the 1D hydrodynamic code MULTI-fs [173] and 2D hydrodynamic code RALEF2D [206] providing the characterization of target electron temperature T e and density n e when the target still remains at solid and near solid density. The simulations are performed in first 100 ps before significant hydrodynamic expansion occurs.…”

Section: Theoretical Modellingmentioning

confidence: 99%

Laser-driven charged particle transport in warm dense matter and plasma

Malko¹

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And of course, I would like thank Jon Apiñaniz, my colleague at work and my friend, who become like a brother for me in the last years. Special thanks for his dedication to our common work, patience and for understanding me so well. Furthermore, I would like to thank Dimitri Batani, who was my supervisor during my internship at CELIA, and provided tremendous help for my research in fast electron transport and shock ignition experiments. I also want to thank Witold Cayzac for his huge contribution in the understanding proton stopping power physics presented in this thesis, Javier Honrubia for the help with the fast electron transport modelling, as well as for the support of this research line, and Frederic Perez for the help in the experimental campaign at LULI-ELFIE facility and for PIC simulations of the fast electron source. I also would like to acknowledge Anna Tauschwitz for performing the RALEF2D simulations. My special thanks are for Micha Ehret, who besides being an awesome friend, with whom you can go to the end of the world, is also a great scientist, who helped me a lot in the LULI-ELFIE experimental campaign. I would like to acknowledge my "proton stopping power rangers" team

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Three-dimensional symmetry analysis of a direct-drive irradiation scheme for the laser megajoule facility

Cited by 12 publications

References 44 publications

Optimizing design of irradiation uniformity of direct drive cone-in-shell target for fast ignition

Optimizing design of irradiation uniformity of direct drive cone-in-shell target for fast ignition

Irradiation uniformity at the Laser MegaJoule facility in the context of the shock ignition scheme

Laser-driven charged particle transport in warm dense matter and plasma

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