Simulations of Mode-Mode Coupling Between Drive Asymmetry and Outer Surface Roughness in Ignition Capsule Implosion

Abstract

Abstract: We perform 2D ignition capsule implosion simulation by a 2D multi-group radiation diffusion hydrodynamic code LARED-S which simultaneously simulates radiation drive asymmetry and outer surface roughness. Implosion flow field shows large-amplitude spikes and bubbles as well as a significant low-mode shell areal density asymmetry. Amplitudes of modes generated by mode coupling are in good agreement with analytic mode coupling equation until perturbation amplitude of fundamental mode L24 is greater than nonlinear saturation amplitude. In deceleration phase, perturbation growth is in strong nonlinear phase, and strong mode coupling effects broaden mode distribution. High-density spikes are bent by vortex flow. Mode coupling degrades greatly implosion performance, leading to ignition failure. Further simulations of mode coupling between low-mode drive asymmetry and capsule surface roughness is critical for understanding influences of hydrodynamic instabilities on ignition capsule implosion.

Key words: inertial confinement fusion, low-mode drive asymmetry, outer surface roughness, mode coupling, turbulent mixing

CLC Number:

O532
O534

GU Jianfa, DAI Zhensheng, GU Peijun, YE Wenhua, ZHENG Wudi, ZOU Shiyang. Simulations of Mode-Mode Coupling Between Drive Asymmetry and Outer Surface Roughness in Ignition Capsule Implosion[J]. CHINESE JOURNAL OF COMPUTATIONAL PHYSICS, 2016, 33(6): 645-651.

References

[1] LINDL J D. Development of the indirect-drive approach to inertial confinement fusion and the target physics basis for ignition and gain[J]. Physics of Plasmas, 1995, 2(11):3933-4024.
[2] LINDL J D, AMENDT P, BERGER R L, et al. The physics basis for ignition using indirect-drive targets on the National Ignition Facility[J]. Physics of Plasmas, 2004, 11(2):339-491.
[3] TAYLOR G. The instability of liquid surfaces when accelerated in a direction perpendicular to their planes[J]. Proc Roy Soc, 1950, 201:192.
[4] CLARK D S, HINKEL D E, EDER D C, et al. Detailed implosion modeling of deuterium-tritium layered experiments on the National Ignition Facility[J]. Physics of Plasmas, 2013, 20:056318.
[5] EDWARDS M J, PATEL P K, LINDL J D, et al. Progress towards ignition on the National Ignition Facility[J]. Physics of Plasmas, 2013, 20:070501.
[6] REGAN S P, EPSTEIN R, HAMMEL B A, et al. Hot-spot mix in ignition-scale inertial confinement fusion targets[J]. Physical Review Letters, 2013, 111:045001.
[7] MA T, PATEL P K, IZUMI N,et al. Onset of hydrodynamic mix in high-velocity, highly compressed inertial confinement fusion implosions[J]. Physical Review Letters, 2013, 111:085004.
[8] TOWN R P J, BRADLEY D K, KRITCHER A, et al. Dynamic symmetry of indirectly driven inertial confinement fusion capsules on the National Ignition Facility[J]. Physics of Plasmas, 2014, 21:056313.
[9] KRITCHER A L, TOWN R, BRADLEY D, et al. Metrics for long wavelength asymmetries in inertial confinement fusion implosions on the National Ignition Facility[J]. Physics of Plasmas, 2014, 21:042708.
[10] GU J F, DAI Z S, FAN Z F, et al. A new metric of the low-mode asymmetry for ignition target designs[J].Physics of Plasmas, 2014, 21:012704.
[11] HAAN S W, LINDL J D, CALLAHAN D A, et al. Point design targets, specifications, and requirements for the 2010 ignition campaign on the National Ignition Facility[J]. Physics of Plasmas, 2011, 18:051001.
[12] HAAN S W, POLLAINE S M, LINDI J D, et al. Design and modeling of ignition targets for the National Ignition Facility[J]. Physics of Plasmas, 1995, 2(6):2480.
[13] MUNRO D H, CELLIERS P M, COLLINS G W, et al. Shock timing technique for the National Ignition Facility[J]. Physics of Plasmas, 2001, 8(5):2245.
[14] YE W H, ZHANG W Y, HE X T. Stabilization of ablative Rayleigh-Taylor instability due to change of the Atwood number[J]. Physical Review E, 2002, 65:057401.
[15] GU J F, DAI Z S, YE W H, et al. Simulation of high-adiabat ICF capsule implosion[J]. Chinese J Comput Phys, 2015, 32(6):662-668.
[16] FENG G T,LAI D X,XU Y,et al. An artificial-scattering iteration method for calculating multigroup transfer problems[J]. Chinese J Comput Phys, 1999, 16(2):199-205.
[17] LI S G, YANG R, HUANG X D. Transport synthetic acceleration methods for multi-group radiative transfer calculations[J]. Chinese J Comput Phys, 2014,31(5):505-513.
[18] TAO Y X, ZHAO Q, CHEN F L. Numerical methods for laser ablation with phase change in two-dimensional code on structured meshes[J].Chinese J Comput Phys,2014,31(2):165-172.
[19] VERDON C P, MCCRORY R L, MORSE R L, et al. Nonlinear effects of multifrequency hydrodynamic instabilities on ablatively accelerated thin shells[J]. Physics of Fluids, 1982, 25:1653.
[20] DAHLBURG J P, GARDNER J H. Ablative Rayleigh-Taylor instability in 3-dimensions[J]. Physical Review A, 1990, 41:5695.
[21] GAMALY E G, LEBO I G, ROZANOV V B, et al. Nonlinear stage in the development of hydrodynamic instability in laser targets[J]. Laser Partical Beams, 1990, 8:173.
[22] HAAN S W. Weakly nonlinear hydrodynamic instabilities in inertial fusion[J]. Physics Fluids B, 1991, 3:2349.
[23] OFER D, SHVARTS D, ZINAMON Z, et al. Mode coupling in nonlinear Rayleigh-Taylor instability[J]. Physics Fluids B, 1992, 4:3549.
[24] HAAN S W. The onset of non-linear saturation for Rayleigh-Taylor growth in the presence of a full spectrum of modes[J]. Physics Review A, 1989, 39:5812.