Linear perturbation response of self-similar ablative flows relevant to inertial confinement fusion

2008 ◽  
Vol 609 ◽  
pp. 1-48 ◽  
Author(s):  
J.-M. CLARISSE ◽  
C. BOUDESOCQUE-DUBOIS ◽  
S. GAUTHIER
Keyword(s):  
Inertial Confinement Fusion ◽  
Similarity Solutions ◽  
Linear Perturbation ◽  
Inertial Confinement ◽  
Mean Flow ◽  
Direct Laser ◽  
Confinement Fusion ◽  
Self Similar ◽  
The Mean ◽  
Compressibility Effects

A family of exact similarity solutions for inviscid compressible ablative flows in slab symmetry with nonlinear heat conduction is proposed for studying unsteadiness and compressibility effects on the hydrodynamic stability of ablation fronts relevant to inertial confinement fusion. Dynamical multi-domain Chebyshev spectral methods are employed for computing both the similarity solution and its time-dependent linear perturbations. This approach has been exploited to analyse the linear stability properties of two self-similar ablative configurations subjected to direct laser illumination asymmetries. Linear perturbation temporal and reduced responses are analysed, evidencing a maximum instability for illumination asymmetries of zero transverse wavenumber as well as three distinct regimes of ablation-front distortion evolution, and emphasizing the importance of the mean flow unsteadiness, compressibility and stratification.

Linear Perturbation Amplification in Self-Similar Ablation Flows of Inertial Confinement Fusion

2006 ◽  
Vol 97 (3) ◽  
Author(s):  
F. Abéguilé ◽  
C. Boudesocque-Dubois ◽  
J.-M. Clarisse ◽  
S. Gauthier ◽  
Y. Saillard
Keyword(s):  
Inertial Confinement Fusion ◽  
Linear Perturbation ◽  
Inertial Confinement ◽  
Confinement Fusion ◽  
Self Similar

Self-similar solutions of unsteady ablation flows in inertial confinement fusion

2008 ◽  
Vol 603 ◽  
pp. 151-178 ◽  
Author(s):  
C. BOUDESOCQUE-DUBOIS ◽  
S. GAUTHIER ◽  
J.-M. CLARISSE
Keyword(s):  
Heat Conduction ◽  
Inertial Confinement Fusion ◽  
Group Symmetry ◽  
Physical Analysis ◽  
Inertial Confinement ◽  
Nonlinear Heat Conduction ◽  
Starting Point ◽  
Confinement Fusion ◽  
Self Similar ◽  
Similar Solutions

We exhibit and detail the properties of self-similar solutions for inviscid compressible ablative flows in slab symmetry with nonlinear heat conduction which are relevant to inertial confinement fusion (ICF). These solutions have been found after several contributions over the last four decades. We first derive the set of ODEs – a nonlinear eigenvalue problem – which governs the self-similar solutions by using the invariance of the Euler equations with nonlinear heat conduction under the two-parameter Lie group symmetry. A sub-family which leaves the density invariant is detailed since these solutions may be used to model the ‘early-time’ period of an ICF implosion where a shock wave travels from the front to the rear surface of a target. A chart allowing us to determine the starting point of a numerical solution, knowing the physical boundary conditions, has been built. A physical analysis of these unsteady ablation flows is then provided, the associated dimensionless numbers (Mach, Froude and Péclet numbers) being calculated. Finally, we show that self-similar ablation fronts generated within the framework of the above hypotheses (electron heat conduction, growing heat flux at the boundary, etc.) and for large heat fluxes and not too large pressures at the boundary do not satisfy the low-Mach-number criteria. Indeed both the compressibility and the stratification of the hot-flow region are too large. This is, in particular, the case for self-similar solutions obtained for energies in the range of the future Laser MegaJoule laser facility. Two particular solutions of this latter sub-family have been recently used for studying stability properties of ablation fronts.

scholarly journals Hydrodynamic instabilities in axisymmetric geometry self-similar models and numerical simulations

2005 ◽  
Vol 23 (2) ◽  
pp. 155-160 ◽  
Author(s):  
J. BREIL ◽  
L. HALLO ◽  
P.H. MAIRE ◽  
M. OLAZABAL-LOUMÉ
Keyword(s):  
Analytical Solution ◽  
Numerical Simulations ◽  
Inertial Confinement Fusion ◽  
Test Case ◽  
Inertial Confinement ◽  
Hydrodynamic Instabilities ◽  
Confinement Fusion ◽  
Self Similar

Hydrodynamic instabilities play an important role in the target compression for inertial confinement fusion (ICF). We present the analytical solution of a perturbed isentropic implosion. We compare the analytical solution to the results obtained with perturbation and bi-dimensional Lagrangian hydrodynamic codes. We also compare results from bi-dimensional code and perturbation code on an ICF like test case.

scholarly journals Self-Similar Structure and Experimental Signatures of Suprathermal Ion Distribution in Inertial Confinement Fusion Implosions

2015 ◽  
Vol 115 (10) ◽  
Author(s):  
Grigory Kagan ◽  
D. Svyatskiy ◽  
H. G. Rinderknecht ◽  
M. J. Rosenberg ◽  
A. B. Zylstra ◽  
...  
Keyword(s):  
Inertial Confinement Fusion ◽  
Inertial Confinement ◽  
Ion Distribution ◽  
Confinement Fusion ◽  
Self Similar ◽  
Fusion Implosions

Analysis of electroless nickel thin films

1991 ◽  
Vol 49 ◽  
pp. 510-511 ◽  
Author(s):  
C. W. Price ◽  
E. F. Lindsey
Keyword(s):  
Thin Films ◽  
Inertial Confinement Fusion ◽  
Electroless Nickel ◽  
Inertial Confinement ◽  
Plating Bath ◽  
X Ray ◽  
Nickel Thin Films ◽  
Nickel Deposits ◽  
Confinement Fusion ◽  
Thickness Measurements

Thickness measurements of thin films are performed by both energy-dispersive x-ray spectroscopy (EDS) and x-ray fluorescence (XRF). XRF can measure thicker films than EDS, and XRF measurements also have somewhat greater precision than EDS measurements. However, small components with curved or irregular shapes that are used for various applications in the the Inertial Confinement Fusion program at LLNL present geometrical problems that are not conducive to XRF analyses but may have only a minimal effect on EDS analyses. This work describes the development of an EDS technique to measure the thickness of electroless nickel deposits on gold substrates. Although elaborate correction techniques have been developed for thin-film measurements by x-ray analysis, the thickness of electroless nickel films can be dependent on the plating bath used. Therefore, standard calibration curves were established by correlating EDS data with thickness measurements that were obtained by contact profilometry.

scholarly journals Pulsed power indirect drive approach to inertial confinement fusion

2020 ◽  
Vol 36 ◽  
pp. 100749 ◽  
Author(s):  
R.E. Olson ◽  
R.J. Leeper ◽  
S.H. Batha ◽  
R.R. Peterson ◽  
P.A. Bradley ◽  
...  
Keyword(s):  
Inertial Confinement Fusion ◽  
Pulsed Power ◽  
Inertial Confinement ◽  
Confinement Fusion ◽  
Indirect Drive

Shell mass effect on the hot-spot pressure in inertial confinement fusion implosion

2021 ◽  
Vol 28 (3) ◽  
pp. 032713
Author(s):  
Dongguo Kang ◽  
Huasen Zhang ◽  
Shiyang Zou ◽  
Wudi Zheng ◽  
Shaoping Zhu ◽  
...  
Keyword(s):  
Inertial Confinement Fusion ◽  
Hot Spot ◽  
Mass Effect ◽  
Inertial Confinement ◽  
Shell Mass ◽  
Confinement Fusion
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