Universal diagram for regimes of<i>Z</i>-pinch stability

Haines, M. G.; Coppins, M.

doi:10.1103/physrevlett.66.1462

Cited by 56 publications

(33 citation statements)

References 29 publications

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“…If ce ei ӷ 1, the plasma is strongly magnetized, and the Hall term ٌ͓ ϫ ͑−j ជ / en e ϫ B ជ ͒, j ជ is current density, and n e is the number density of electron͔ and diamagnetic pressure term ٌ͓ ϫ ͑1 / en e ٌ p e ͒ and p e is the electron pressure͔ would not be neglected in the evolution equation of magnetic field. 46 Whereas the two terms can be ignored if ce ei Ӷ 1 due to / en e ͑j ជ ϫ B ជ ͒ = ce ei j ជ ϫ B ជ / B. From Fig.…”

Section: B the Degree Of The Plasma Magnetizationmentioning

confidence: 97%

Numerical studies of the effects of precursor plasma on the performance of wire-array Z-pinches

et al. 2010

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This paper is to numerically investigate, in one dimension, the effects of precursor plasma resulted from wire-array ablation on the performance of its following implosion after the ablation. The wire-array ablation is described by an analytic model, which consists of a rocket model or Sasorov's expression of wire-array mass ablation rate, the evolution equation of magnetic field, and several roughly reasonable assumptions. The following implosion is governed by the radiation magnetohydrodynamics. The implosion processes of wire-array Z-pinch from plasma shells prefilled and un-prefilled by the low-density plasma inside them are studied, and that from the wire-array ablations, which may be changed through varying the ablation time, ablation rate, and ablation velocity V abl , are also simulated. The obtained results reveal that the prefilled low-density plasma and the precursor plasma from the wire-array ablation help to enhance the plasma shell pinch and the final implosion of the wire array, respectively, compared to the pinch of un-prefilled plasma shell. With the same plasma masses, which are distributed in the interior of the array and the shell, and modified Spitzer resistivity, the implosions that start from the wire ablation develop faster than that from the plasma shell with the prefill. If more substance ablates from the wire array before the start of its implosion, the final Z-pinch performance could be better. The Z-pinch plasma is highly magnetized with driven current more than 3 MA.

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Section: B the Degree Of The Plasma Magnetizationmentioning

confidence: 97%

Numerical studies of the effects of precursor plasma on the performance of wire-array Z-pinches

et al. 2010

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“…8,9 A universal diagram has been found for an equilibrium Z pinch. 10 However, for dynamic Z pinches, in particular the imploding wire-array pinch, the Rayleigh-Taylor ͑R-T͒ instability is dominant and in a regime where collisional fluid MHD largely applies, just as in inertial confinement, and, like ICF, there is much advantage in minimizing the initial seed perturbation. In the case of the Z pinch, this leads to a higher compression on stagnation and a sharper and more intense x-ray pulse.…”

Section: Introductionmentioning

confidence: 99%

The past, present, and future of Z pinches

et al. 2000

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The Z pinch is enjoying a renaissance as the world's most powerful yet efficient soft x-ray source which can energize large volume hohlraums for indirectly driven inertial confinement fusion. It has the advantages of being efficient and having high energy and power density. Its early history will be traced from the 18th century to the present day. The most notable feature of the Z pinch is its instability. The various regimes of stability analysis will be reviewed, including resistive and finite ion Larmor radius effects. Work in the last 10 years on single fibres, especially of cryogenic deuterium, gave neutrons that were of the same origin, namely, beam-plasma interactions, as reported by Kurchatov. The renaissance has come about through the implosion of arrays of fine wires. Research at Sandia National Laboratory has shown that by using more and finer wires, the x-ray radiation emitted at stagnation increased in power and decreased in pulse width. The understanding of these results has been advanced considerably by theory, simulation and smaller-scale, well diagnosed experiments showing the early uncorrelated mϭ0 instabilities on each wire, the inward jetting of plasma to the axis, the global Rayleigh-Taylor instability and the mitigating effect of nested arrays.

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“…In addition only the solutions that could results in a z-pinch with enhanced stability were selected. In fact, it has been theoretically conjectured that there is a threshold for the stabilization due to resistive effects, corresponding to a Lundquist number S∼100 (S=3.87x10 23 I 4 aN -2 , for a pinch in deuterium [4]). Experimentally, it has been observed that for Z-pinch discharges with a substantially lower value of S, no instabilities appear.…”

Section: Gas Embedded Z-pinchmentioning

confidence: 99%

“…for a pinch in deuterium [1][2][3][4]). This is consistent with theoretical studies which indicate that the region of minimum instability for pinch discharges is in the neighborhood of a i /a~0.2 [5,6].…”

Section: Gas Embedded Z-pinchmentioning

confidence: 99%