Mitigation of Instabilities in a Z-Pinch Plasma by a Preembedded Axial Magnetic Field

Mikitchuk, D.; Stollberg, Christine; Doron, R.; Kroupp, E.; Maron, Y.; Strauss, H. R.; Velikovich, A. L.; Giuliani, J. L.

doi:10.1109/tps.2014.2327094

Cited by 37 publications

(17 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the first method, the stabilization mechanism works as follows: the magnetic shear between the compressed magnetic field B z inside a Z-pinch and the compressive azimuthal magnetic field B θ outside it enhances the stability of the imploding plasma shell and suppresses the growth of MRT instabilities [2,[16][17][18]. The implosion of Z-pinches can be stabilized by comparatively low B z fields [17]. This method makes it possible to suppress the most dangerous MRT instability, the wavelength of which is approximately equal to the thickness of the current sheath [2].…”

Section: Introductionmentioning

confidence: 99%

Effect of tailored density profiles on the stability of imploding Z-pinches at microsecond rise time megaampere currents

Cherdizov¹,

Baksht²,

Kokshenev³

et al. 2021

Plasma Phys. Control. Fusion

View full text Add to dashboard Cite

To study the effect of the radial density profile of the material of a metal-plasma Z-pinch load on the development of magneto-Rayleigh-Taylor (MRT) instabilities, experiments have been performed at the Institute of High Current Electronics with the GIT-12 generator produced microsecond rise time megaampere currents. The load was an aluminum plasma jet with an outer plasma shell. This configuration provides the formation of a uniform current sheath in a Z-pinch load upon application of a high voltage pulse. It was successfully used in experiments with hybrid deuterium gas-puffs [Klir et al. 2020 New J. Phys. 22 103036]. The initial density profiles of the Z-pinch loads were estimated from the pinch current and voltage waveforms using the zero-dimensional "snowplow" model, and they were verified by simulating the expansion of the plasma jet formed by a vacuum arc using a two-dimensional quasi-neutral hybrid model [Shmelev et al. 2020 Phys. Plasmas 27 092708]. Two Z-pinch load configurations were used in the experiments. The first configuration provided tailored load density profiles, which could be described as ρ(r) ≈ 1/r^s for s > 2. In this case, MRT instabilities were suppressed and thus a K-shell radiation yield of 11 kJ/cm and a peak power of 0.67 TW/cm could be attained at a current of about 3 MA. For the second configuration, the radial density profiles were intentionally changed using a reflector. This led to the appearance of a notch in the density profiles at radii of 1–3 cm from the pinch axis and to magnetohydrodynamic instabilities at the final implosion stage. As a result, the K-shell radiation yield more than halved and the power decreased to 0.15 TW/cm at a current of about 3.5 MA.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of tailored density profiles on the stability of imploding Z-pinches at microsecond rise time megaampere currents

Cherdizov¹,

Baksht²,

Kokshenev³

et al. 2021

Plasma Phys. Control. Fusion

View full text Add to dashboard Cite

show abstract

“…Filamentation instabilities, which give rise to the formation of individual current channels, are often observed in experiments with plasma focuses [27,28] and Z pinches [29,50,51]. As noted above, the most probable reason for the appearance of filaments is the development of thermal instabilities, the structure of which is determined by the nature of the dependence of the resistivity of the material on temperature and density.…”

Section: Filamentation Modelmentioning

confidence: 96%

Filamentation of the surface plasma layer during the electrical explosion of conductors in strong magnetic fields

Oreshkin

Chaikovsky

Datsko

et al. 2022

Journal of Applied Physics

View full text Add to dashboard Cite

A model has been considered to describe the development of a surface discharge over a conductor electrically exploding in a strong magnetic field. A simulation performed using this model has shown that in the initial stage of the conductor explosion, a plasma layer of several tens of micrometers thick with an electron temperature of several electronvolts is formed on the metal surface. Based on the theory of small perturbations, the development of thermal filamentation instabilities that form in the surface plasma layer has been analyzed. The characteristic growth rates and wavelengths of these instabilities have been determined. The theoretical results were compared with the results of experiments performed on the ZEBRA generator (providing load currents of amplitude about 1 MA and rise time about 100 ns) and on the MIG generator (providing load currents of amplitude about 2 MA and rise time about 100 ns). For the conditions implemented with these generators, the filamentation model gives rise times of thermal filamentation instabilities of tens of nanoseconds at characteristic wavelengths of the order of 100 μm. These values are in good agreement with experimental data, which indicates the adequacy of both the surface discharge development model and the filamentation model.

show abstract

“…8,[33][34][35][36] Different methods for mitigation or control of such instabilities are actively studied at present. 34,37,38 At the same time, the diocotron and slipping instabilities could be useful for the development of novel methods for HPM generation (see, for example, the work 23 where the effect of the microwave generation from the filamentation and vortex formation within magnetically confined electron beams was discovered and investigated).…”

Section: Introductionmentioning

confidence: 99%

The development and interaction of instabilities in intense relativistic electron beams

et al. 2015

View full text Add to dashboard Cite

We report on the physical mechanisms of development, coexistence and interaction of Pierce-Bursian and diocotron instabilities in the non-neutral relativistic electron beam (REB) in the classic vircator. The analytical and numerical analysis is provided by means of 3D electromagnetic simulation. We conducted an extensive study of characteristic regimes of REB dynamics determined by the instabilities development. As a result, a regime map has been obtained. It demonstrates sequential switching of the REB dynamics from the regime with N ¼ 1 to the regime with N ¼ 7 electron bunches in the azimuth direction with the beam current growth for the different external magnetic fields. The numerical analysis of bunch equilibrium states has identified the physical causes responsible for the REB regime switchings. V

show abstract

Mitigation of Instabilities in a Z-Pinch Plasma by a Preembedded Axial Magnetic Field

Cited by 37 publications

References 5 publications

Effect of tailored density profiles on the stability of imploding Z-pinches at microsecond rise time megaampere currents

Effect of tailored density profiles on the stability of imploding Z-pinches at microsecond rise time megaampere currents

Filamentation of the surface plasma layer during the electrical explosion of conductors in strong magnetic fields

The development and interaction of instabilities in intense relativistic electron beams

Contact Info

Product

Resources

About