Stabilization of beam-weibel instability by equilibrium density ripples

Mishra, S. K.; Kaw, P. K.; Das, Amita; Sengupta, Sudip; Kumar, G. Ravindra

doi:10.1063/1.4862175

Cited by 8 publications

(13 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A recent experimental [19]result, has shown many fold improvement in the propagation of a hot relativistic electron beam through an array of carbon nanotubes (CNTs). An explanation of this has been put forth by Mishra et al [20] suggesting that the inhomogeneous plasma created by the ionization of the CNTs by the front of the beam is responsible for the stabilization of transverse instabilities, thereby aiding the collimated propagation of the beam through longer distances compared to a homogeneous plasma. Here we carry out the PIC simulations to study the role of inhomogeneity with arbitrary amplitude, on the propagation of electron beam through plasma.…”

Section: Introductionmentioning

confidence: 99%

1D3V PIC simulation of propagation of relativistic electron beam in an inhomogeneous plasma

Shukla¹,

Das²,

Patel³

2015

Phys. Scr.

View full text Add to dashboard Cite

A recent experimental observation has shown efficient transport of Mega Ampere of electron currents through aligned carbon nanotube arrays [Phys. Rev Letts. 108, 235005 (2012)]. The result was subsequently interpreted on the basis of suppression of the filamentation instability in an inhomogeneous plasma [Phys. Plasmas 21, 012108 (2014)]. This inhomogeneity forms as a result of the ionization of the carbon nanotubes. In the present work a full 1D3V Particle-in-Cell (PIC) simulations have been carried out for the propagation of relativistic electron beams (REB) through an inhomogeneous background plasma. The suppression of the filamentation instability, responsible for beam divergence, is shown. The simulation also confirms that in the nonlinear regime too the REB propagation is better when it propagates through a plasma whose density is inhomogeneous transverse to the beam. The role of inhomogeneity scale length, its amplitude and the transverse beam temperature etc., in the suppression of the instability is studied in detail.

show abstract

Section: Introductionmentioning

confidence: 99%

1D3V PIC simulation of propagation of relativistic electron beam in an inhomogeneous plasma

Shukla¹,

Das²,

Patel³

2015

Phys. Scr.

View full text Add to dashboard Cite

show abstract

“…Actually, this gap becomes discernible for ξ 3.5, and results in a progressive quelling of the modes in the range k 0 /2 ≤ k y ≤ k 0 . Stabilization of the low-k y modes is also specific to the strongly inhomogeneous regime; this mechanism underlines a recently proposed scheme, which exploits density ripples to mitigate the CFI in the laserplasma context [103]. We now perform a full 2D stability analysis of the equilibrium filamentary state by considering nonzero values of the longitudinal wavenumber k x .…”

Section: D Instability Of Strongly Nonlinear Symmetric Filamentsmentioning

confidence: 81%

Stability analysis of a periodic system of relativistic current filaments

2018

View full text Add to dashboard Cite

The nonlinear evolution of current filaments generated by the Weibel-type filamentation instability is a topic of prime interest in space and laboratory plasma physics. In this paper, we investigate the stability of a stationary periodic chain of nonlinear current filaments in counterstreaming pair plasmas. We make use of a relativistic four-fluid model and apply the Floquet theory to compute the two-dimensional unstable eigenmodes of the spatially periodic system. We examine three different cases, characterized by various levels of nonlinearity and asymmetry between the plasma streams: a weakly nonlinear symmetric system, prone to purely transverse merging modes; a strongly nonlinear symmetric system, dominated by coherent drift-kink modes whose transverse periodicity is equal to, or an integer fraction of the unperturbed filaments; a moderately nonlinear asymmetric system, subject to a mix of kink and bunching-type perturbations. The growth rates and profiles of the numerically computed eigenmodes agree with particle-in-cell simulation results. In addition, we derive an analytic criterion for the transition between dominant filament-merging and drift-kink instabilites in symmetric two-beam systems.

show abstract

“…If the ripple size is larger than the aligning period of layers, the growing rate of perturbation will be suppressed, because the fast electron transportation from the low-density regions to high density regions is impeded. On the other hand, for the ripples whose transverse size smaller than the layer width, if the layer period is engineered shorter than the skin depth, it is a well-known fact that the transverse electromagnetic perturbations are also weakened [18]. Consequently, we can get results: for a multi-layer structure, the magnetic instability (with large k, i.e., small size) can be suppressed by decreasing the layer width, while the magnetic instability across layers (with small k, i.e., large size) can be suppressed by increasing the resistive magnetic field at the interfaces between adjacent layers with different Z.…”

Section: Theorymentioning

confidence: 99%

“…Recently, many efforts in this direction have been reported [14][15][16][17]. Especially, in the work of [18], Mishra et al present an approach to achieve suppression/complete stabilization of the transverse electromagnetic beam Weibel instability by periodically modifying the electron density of background with an equilibrium density ripple, shorter than the skin depth. Recent experiments have shown that the intense laser-driven MeV electron beam can effectively transport over millimeters in carbon nanotube array, 100 times longer than the typical filament length in solid target [19].…”

Section: Introductionmentioning

confidence: 99%

The Weakened Weibel Electromagnetic Instability of Ultra-Intense Mev Electron Beams in Multi-Layer Solid Structure

Liao¹,

Zhao²

2017

PIER M

View full text Add to dashboard Cite

Abstract-The Weibel instability of intense and collimated MeV fast electron beams in multi-layer structure is investigated. It is found that the electromagnetic instability of fast electron beams can be significantly suppressed by this structure. A strong magnetic field will be created at the interfaces between materials with different resistivities as these fast electrons are injected into this structure. It obstructs the transverse movement of the fast electrons and confines them to propagate along the interfaces. In consequence, the positive feedback loop between magnetic field perturbation and electrons density perturbation is broken, and the Weibel instability is thus weakened. Furthermore, the calculated results for Au/Si multi-layer structure by a hybrid Particle in Cell code have proven this weakening effect on the Weibel instability of intense fast electron beams. Because of the high energy-density delivered by the MeV electrons, these results indicate applications in high-energy physics, such as radiography, fast electron beam focusing, and perhaps fast ignition.

show abstract

Stabilization of beam-weibel instability by equilibrium density ripples

Cited by 8 publications

References 32 publications

1D3V PIC simulation of propagation of relativistic electron beam in an inhomogeneous plasma

1D3V PIC simulation of propagation of relativistic electron beam in an inhomogeneous plasma

Stability analysis of a periodic system of relativistic current filaments

The Weakened Weibel Electromagnetic Instability of Ultra-Intense Mev Electron Beams in Multi-Layer Solid Structure

Contact Info

Product

Resources

About