New designs of LMJ targets for early ignition experiments

C-Clérouin, C; Bonnefille, Max; Dattolo, E.; Fremerye, P.; Galmiche, D.; Gauthier, P.; Giorla, J.; Laffite, S.; Liberatore, S.; Loiseau, P.; Malinie, G.; Massé, L.; Poggi, F.; Seytor, P.

doi:10.1088/1742-6596/112/2/022023

Cited by 4 publications

(3 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In accordance with the available laser technologies and envisioned costs of a behemoth 5 MJ laser, the laser energy was downscaled to 2 MJ with some margins for ignition. In fact, prior to the National Ignition Campaign (NIC) [21], 2D radiation hydrodynamics simulations were still predicting high fusion gain with less than 2 MJ in indirect drive [42,43]. Nowadays, the most accurate 3D radiation hydrodynamics capsule only simulations are used to extrapolate performances of moderate convergent implosions with 5 MJ of laser energy [44,45].…”

Section: Hydrodynamics Instabilities In Inertial Confinement Fusion (mentioning

confidence: 99%

Recent progress in quantifying hydrodynamics instabilities and turbulence in inertial confinement fusion and high-energy-density experiments

Casner

2020

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

Since the seminal paper of Nuckolls triggering the quest of inertial confinement fusion (ICF) with lasers, hydrodynamic instabilities have been recognized as one of the principal hurdles towards ignition. This remains true nowadays for both main approaches (indirect drive and direct drive), despite the advent of MJ scale lasers with tremendous technological capabilities. From a fundamental science perspective, these gigantic laser facilities enable also the possibility to create dense plasma flows evolving towards turbulence, being magnetized or not. We review the state of the art of nonlinear hydrodynamics and turbulent experiments, simulations and theory in ICF and high-energy-density plasmas and draw perspectives towards in-depth understanding and control of these fascinating phenomena. This article is part of a discussion meeting issue ‘Prospects for high gain inertial fusion energy (part 2)’.

show abstract

Section: Hydrodynamics Instabilities In Inertial Confinement Fusion (mentioning

confidence: 99%

Recent progress in quantifying hydrodynamics instabilities and turbulence in inertial confinement fusion and high-energy-density experiments

Casner

2020

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

show abstract

“…3 The A1040 capsule encased in a "rugby-shaped" hohlraum is also a candidate for the first ignition attempts that will be undertaken with 160 beams before the total facility completion. 12,13 The spherical capsule is composed of a 100 m thick cryogenic deuterium-tritium shell with an ex-ternal radius of 1040 m, covered by a plastic ͑CH͒ ablator nonuniformly doped with germanium. The ablator includes two pure CH layers surrounding two doped layers to reduce the growth of short wavelength hydrodynamic instabilities.…”

Section: Base Line and 1d Parametersmentioning

confidence: 99%

A metamodeling approach for studying ignition target robustness in a highly dimensional parameter space

et al. 2009

View full text Add to dashboard Cite

Inertial confinement fusion targets must be carefully designed to ignite their central hot spots and burn. Changes in the optimal implosion could reduce the fusion energy or even prevent ignition. Since there are unavoidable uncertainties due to technological defects and not perfect reproducibility from shot to shot, the fusion energy will remain uncertain. The degree with which a target can tolerate larger specifications than specified, and the probability with which a particular yield is exceeded, are possible measures of the robustness of that design. This robustness must be assessed in a very high-dimensional parameter space whose variables include every characteristics of the given target and of the associated laser pulse shape, using high-fidelity simulations. Therefore, these studies would remain computationally very intensive. In this paper we propose an approach which consist first of constructing an accurate metamodel of the yield on the whole parameter space with a reasonable data set of simulations. Then the robustness is very quickly assessed for any set of specifications with this surrogate. The yield is approximated by a neural network, and an iterative method adds new points in the data set by means of D-optimal experimental designs. The robustness study of the baseline Laser Mégajoule target against one-dimensional defects illustrates this approach. A set of 2000 simulations is sufficient to metamodel the fusion energy on a large 22-dimensional parameter space around the nominal point. Furthermore, a metamodel of the robustness margin against all specifications has been obtained, providing guidance for target fabrication research and development.

show abstract

“…The experimental plans include the attempt of ignition and burn of an ICF capsule with 160 beams in 2 cones (33.2 • and 49 • ), delivering up to 1.4 MJ and 380 TW at 3ω. New targets needing reduced laser energy with only a small decrease in robustness have been designed for this purpose [6]. They are presented in section 3.…”

Section: Introductionmentioning

confidence: 99%

Progress on LMJ targets for ignition

Cherfils-Clérouin

Boniface

Bonnefille

et al. 2009

Plasma Phys. Control. Fusion

Self Cite

View full text Add to dashboard Cite

Targets designed to produce ignition on the Laser Megajoule (LMJ) are being simulated in order to set specifications for target fabrication. The LMJ experimental plans include the attempt of ignition and burn of an ICF capsule with 160 laser beams, delivering up to 1.4 MJ and 380 TW. New targets needing reduced laser energy with only a small decrease in robustness have then been designed for this purpose. Working specifically on the coupling efficiency parameter, i.e. the ratio of the energy absorbed by the capsule to the laser energy, has led to the design of a rugby-ball shaped cocktail hohlraum; with these improvements, a target based on the 240-beam A1040 capsule can be included in the 160-beam laser energy-power space. Robustness evaluations of these different targets shed light on critical points for ignition, which can trade off by tightening some specifications or by preliminary experimental and numerical tuning experiments.

show abstract

New designs of LMJ targets for early ignition experiments

Cited by 4 publications

References 8 publications

Recent progress in quantifying hydrodynamics instabilities and turbulence in inertial confinement fusion and high-energy-density experiments

Recent progress in quantifying hydrodynamics instabilities and turbulence in inertial confinement fusion and high-energy-density experiments

A metamodeling approach for studying ignition target robustness in a highly dimensional parameter space

Progress on LMJ targets for ignition

Contact Info

Product

Resources

About