Computational investigation of the magneto-Rayleigh–Taylor instability in Z-pinch implosions

Zhang, Yang; Wu, Jiming; Dai, Zhensheng; Ding, Ning; Ning, Cheng; Yanzhong, Yao; Xiao, Di; Sun, Shunkai; Gu, Tingyue; Cao, Yi; Huang, Jun; Xue, Cun; Shu, Xiaojian

doi:10.1063/1.3381072

Cited by 6 publications

(3 citation statements)

References 19 publications

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“…[22] The evolution to longer wavelengths was observed in many numerical simulations. [23] The mm-scale dominant wavelength is in good agreement with the experimental data in Ref. [24].…”

Section: The Images Of the Implosionsupporting

confidence: 84%

Radiation characteristics and implosion dynamics of tungsten wire array Z-pinches on the YANG accelerator

Huang¹,

Yang²,

Li³

et al. 2012

Chinese Phys. B

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We investigated the radiation characteristics and implosion dynamics of low-wire-number cylindrical tungsten wire array Z-pinches on the YANG accelerator with a peak current 0.8-1.1 MA and a rising time ∼ 90 ns. The arrays are made up of (8-32)×5 µm wires 6/10 mm in diameter and 15 mm in height. The highest X-ray power obtained in the experiments was about 0.37 TW with the total radiation energy ∼ 13 kJ and the energy conversion efficiency ∼ 9% (24×5 µm wires, 6 mm in diameter). Most of the X-ray emissions from tungsten Z-pinch plasmas were distributed in the spectral band of 100-600 eV, peaked at 250 and 375 eV. The dominant wavelengths of the wire ablation and the magneto-Rayleigh-Taylor instability were found and analyzed through measuring the time-gated self-emission and laser interferometric images. Through analyzing the implosion trajectories obtained by an optical streak camera, the run-in velocities of the Z-pinch plasmas at the end of the implosion phase were determined to be about (1.3-2.1)×10 7 cm/s.

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“…[22] The evolution to longer wavelengths was observed in many numerical simulations. [23] The mm-scale dominant wavelength is in good agreement with the experimental data in Ref. [24].…”

Section: The Images Of the Implosionsupporting

confidence: 84%

Radiation characteristics and implosion dynamics of tungsten wire array Z-pinches on the YANG accelerator

Huang¹,

Yang²,

Li³

et al. 2012

Chinese Phys. B

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“…Other parameters, such as wire-array masses and radii, converter mass densities and radii, and ablator and fuel radii, are varied for different drive currents to obtain a relatively optimal hohlraum. The dynamics of a dynamic hohlraum driven target implosion is simulated by a three-temperature radiation MHD code in one dimension, 22 and over 249 total grids are used in simulations.…”

Section: Radiation Ablation and Shock Compressionmentioning

confidence: 99%

Numerical investigation on target implosions driven by radiation ablation and shock compression in dynamic hohlraums

et al. 2015

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In a dynamic hohlraum driven inertial confinement fusion (ICF) configuration, the target may experience two different kinds of implosions. One is driven by hohlraum radiation ablation, which is approximately symmetric at the equator and poles. The second is caused by the radiating shock produced in Z-pinch dynamic hohlraums, only taking place at the equator. To gain a symmetrical target implosion driven by radiation ablation and avoid asymmetric shock compression is a crucial issue in driving ICF using dynamic hohlraums. It is known that when the target is heated by hohlraum radiation, the ablated plasma will expand outward. The pressure in the shocked converter plasma qualitatively varies linearly with the material temperature. However, the ablation pressure in the ablated plasma varies with 3.5 power of the hohlraum radiation temperature. Therefore, as the hohlraum temperature increases, the ablation pressure will eventually exceed the shock pressure, and the expansion of the ablated plasma will obviously weaken the shock propagation and decrease its velocity after propagating into the ablator plasma. Consequently, longer time duration is provided for the symmetrical target implosion driven by radiation ablation. In this paper these processes are numerically investigated by changing drive currents or varying load parameters. The simulation results show that a critical hohlraum radiation temperature is needed to provide a high enough ablation pressure to decelerate the shock, thus providing long enough time duration for the symmetric fuel compression driven by radiation ablation. V C 2015 AIP Publishing LLC.

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“…Z-pinches are thus inherently susceptible to Magneto-Rayleigh-Taylor (MRT) instabilities, especially for large-radius and long-time implosions. This instability 11,12 occurs at the plasma-magnetic piston interface and is believed to be capable of degrading implosion symmetry and limiting the Z-pinch source performance. 13 The HVM of EUV lithography requires the light source not only to have efficient output power but also to have high spatial stability, pulse-to-pulse energy stability, and a smaller spot size.…”

Section: Introductionmentioning

confidence: 99%

Simulation and mitigation of the magneto-Rayleigh-Taylor instabilities in Z-pinch gas discharge extreme ultraviolet plasma radiation sources

et al. 2013

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The development and use of a single-fluid two-temperature approximated 2-D MagnetoHydrodynamics code is reported. Z-pinch dynamics and the evolution of Magneto-Rayleigh-Taylor (MRT) instabilities in a gas jet type Extreme Ultraviolet (EUV) source are investigated with this code. The implosion and stagnation processes of the Z-pinch dynamics and the influence of initial perturbations (single mode, multi-mode, and random seeds) on MRT instability are discussed in detail. In the case of single mode seeds, the simulation shows that the growth rates for mm-scale wavelengths up to 4 mm are between 0.05 and 0.065 ns À1 . For multi-mode seeds, the mode coupling effect leads to a series of other harmonics, and complicates MRT instability evolution. For perturbation by random seeds, the modes evolve to longer wavelengths and finally converge to a mm-scale wavelength approximately 1 mm. MRT instabilities can also alter the pinch stagnation state and lead to temperature and density fluctuations along the Z axis, which eventually affects the homogeneity of the EUV radiation output. Finally, the simulation results are related to experimental results to discuss the mitigations of MRT instability. V C 2013 AIP Publishing LLC.

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Computational investigation of the magneto-Rayleigh–Taylor instability in Z-pinch implosions

Cited by 6 publications

References 19 publications

Radiation characteristics and implosion dynamics of tungsten wire array Z-pinches on the YANG accelerator

Radiation characteristics and implosion dynamics of tungsten wire array Z-pinches on the YANG accelerator

Numerical investigation on target implosions driven by radiation ablation and shock compression in dynamic hohlraums

Simulation and mitigation of the magneto-Rayleigh-Taylor instabilities in Z-pinch gas discharge extreme ultraviolet plasma radiation sources

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