Inverse Liner Z-Pinch: An Experimental Pulsed Power Platform for Studying Radiative Shocks

Clayson, Thomas; Lebedev, S. V.; Suzuki-Vidal, F.; Burdiak, G.; Halliday, J. W. D.; Hare, Jack; Suttle, L.; Tubman, Eleanor

doi:10.1109/tps.2018.2868757

Cited by 5 publications

(1 citation statement)

References 26 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…还有研究者利用X箍缩点源对薄膜爆炸发展过程的形态结构开展成像分析 [15−17] , 对金属薄膜的核冕结构和等离子体膨胀速度开展定量研究 [18] 等. 击波研究 [19] 、大型圆柱丝阵局部等离子体行为模拟 [20,21] 、天体物理中等离子体间的碰撞 [22] 等领域内皆有应用.…”

unclassified

Explosion of thin flat foils with periodical modified structure

Liu¹,

Liang²,

Li³

et al. 2021

Acta Phys. Sin.

View full text Add to dashboard Cite

The fast Z-pinch plasma formation, exploding dynamics, and the evolution of the instability can be controlled experimentally by making special structures on metal surface layer to change the initial state of material, which is valuable for studying the Z-pinch physics. Experiments on the explosion of thin flat foils which have been etched into a periodical structure on surface are performed on the QG-1 facility (～1.4 MA peak current, ～100 ns rise time) in order to study the effects of different surface conditions on explosion and control the evolution of the instability in fast Z-pinch plasma. A kind of inverse load configuration is used in experiment in which the return current post is set at the central axial-position and two modified flat foils are strained outside symmetrically as the main load. So the corresponding J × B force directs outward from the return current post orthogonal to the foil plane, creating an acceleration and pushing the foil plasma away from the center in this configuration. Different surfaces of the foil are also investigated in different conditions because of the asymmetric magnetic field distribution which is useful to study the different evolutions of instability. The foils used in the experiment mainly are the 30-μm-thick aluminum foil. The wavelength of groove perturbations seeded on the surface is 2 mm wide and ～10 μm deep. The plasma explosion dynamic behaviors around conditioned area are diagnosed by laser shadowgraphy, laser interferometry, multiframe optical self-emission imaging and B-dot. It is found that the initially etched periodical structure on surface can control the plasma structure in exploding process which can be concluded as follows. Developing plasma structure shows a periodic character similar to the initial surface structure and the eigenwavelength of the Al is suppressed. In the meantime, the surface without etched perturbations is also influenced by the etched side, showing a similar instability structure but with a lower amplitude. The correlation between two surfaces turns stronger than the case of normal foils. A faster expanding rate occurs in the deep region of the initial periodical groove structure which causes a reverse structure to form. In the discontinuous area of the conditoned structure, a narrow stream of plasma jets perpendicularly from the metal surface which causes a half-wavelength to occur in spectrum analysis. The magneto-hydro-dynamic theory analysis shows that the change of electrothermal instabilities is caused dominantly by the modulation of current density flowing around the periodical structure.

show abstract

unclassified

Explosion of thin flat foils with periodical modified structure

Liu¹,

Liang²,

Li³

et al. 2021

Acta Phys. Sin.

View full text Add to dashboard Cite

show abstract

Visualizing magnetically driven converging radiative shock generated in Z-pinch foil liner implosion

Meng

Zhang

et al. 2021

Physics of Plasmas

View full text Add to dashboard Cite

A study of the evolution and structure of magnetically driven converging radiative shock waves generated in Z-pinch foil liner implosion at an 8-MA pulsed-power facility is presented. End-on extreme ultraviolet images show an inward propagating shock that is circular to <±5% as a function of azimuthal angle, with a standard deviation in the emission intensity of <±30%, implying good cylindrical symmetry. The launch time and shock trajectory are determined by linear fitting of the measured data, giving a shock speed of Mach 6. One-dimensional radiation hydrodynamics MULTI-IFE-Z simulations agree with the experimental observations qualitatively and confirm the existence of a radiative precursor. It is demonstrated with experiment and simulation that the radiative shock wave is generated by magnetic piston compression of dense plasma shell. Analytic estimates of the post-shock plasma conditions suggest that these Z-pinch magnetically-driven high-Mach shocks are strongly radiatively cooled. It is applicable to the optically thick downstream, optically thin upstream radiative shock regime; thus, it can be described by three-layer model, which potentially could be applied to scale studies of astrophysical shocks in the laboratory.

show abstract

Analytical study of ionizing blast waves in atomic hydrogen

2023

View full text Add to dashboard Cite

The ionization effect on both the evolution and internal structure of a blast wave (BW) is determined in laboratory conditions. In a first step, the Rankine–Hugoniot equations describing the structure of the shock front together with the Saha equation modeling ionization are solved analytically in a consistent way for the conditions of a cold initial atomic hydrogen gas. In a second step, a simplified approach is used by introducing an effective adiabatic index γ * that takes into account ionization arising at the shock front. Finally, γ * is used as input data in the self-similar model derived formerly by Barenblatt to describe the structure and the dynamics of the ionizing BW. For the typical laboratory conditions of blast wave experiments, ionization achieves a hydrogen gas compression up to about 11 times at the shock front of the blast wave where a thin and dense shell forms. For such a compression, the value of the effective adiabatic index is γ * ≃ 1.2 leading to a self-similar evolution of the BW where its radius R(t) varies according to R ( t ) ∝ t α * with α * ≃ 0.33. This value of α * is lower than the adiabatic expansion stage α = 2 / 5, where the total energy of the BW is conserved. Thus, ionization is found to act as a cooling effect at the shock front where a fraction of kinetic energy is absorbed to ionize the gas.

show abstract

Inverse Liner Z-Pinch: An Experimental Pulsed Power Platform for Studying Radiative Shocks

Cited by 5 publications

References 26 publications

Explosion of thin flat foils with periodical modified structure

Explosion of thin flat foils with periodical modified structure

Visualizing magnetically driven converging radiative shock generated in Z-pinch foil liner implosion

Analytical study of ionizing blast waves in atomic hydrogen

Contact Info

Product

Resources

About