The pinch effect in pulsed streams at relativistic energies

Roberts, T. G.; Bennett, Willard H.

doi:10.1088/0032-1028/10/4/305

Cited by 43 publications

(4 citation statements)

References 2 publications

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Section: Introductionmentioning

confidence: 99%

“…It has been known for a long time that a return current arises in a plasma penetrated by an external beam current [1]. A theory of this phenomenon for the laboratory plasma has been developed in a number of previous papers [1][2][3][4][5]. It was shown that the induced plasma current depends on the spatio-temporal shape of the imposed current and is transferred by plasma species.…”

Section: Introductionmentioning

confidence: 99%

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Back-reaction instabilities of relativistic cosmic rays

Nekrasov¹

2013

Plasma Phys. Control. Fusion

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We explore streaming instabilities of the electron-ion plasma with relativistic and ultra-relativistic cosmic rays in the background magnetic field in the multi-fluid approach.Cosmic rays can be both electrons and ions. The drift speed of cosmic rays is directed along the magnetic field. In equilibrium, the return current of the background plasma is taken into account. One-dimensional perturbations parallel to the magnetic field are considered.The dispersion relations are derived for transverse and longitudinal perturbations. It is shown that the back-reaction of magnetized cosmic rays generates new instabilities one of which has the growth rate that can approach the growth rate of the Bell instability. These new instabilities can be stronger than the cyclotron resonance instability. For unmagnetized cosmic rays, the growth rate is analogous to the Bell one. We compare two models of the plasma return current in equilibrium with three and four charged components. Some difference between these models is demonstrated. For longitudinal perturbations, an instability is found in the case of ultra-relativistic cosmic rays. The results obtained can be applied to investigation of astrophysical objects such as the shocks by supernova remnants, galaxy clusters, intracluster medium and so on, where interaction of cosmic rays with turbulence of the electron-ion plasma produced by them is of a great importance for the cosmic-ray evolution.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Back-reaction instabilities of relativistic cosmic rays

Nekrasov¹

2013

Plasma Phys. Control. Fusion

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“…It is known for a long time that a return current is induced in a plasma penetrated by an external beam current (Roberts & Bennett 1968). The return plasma current equal to the external one and directed oppositely arises due to self-consistent electromagnetic perturbations of plasma under the action of an external current (e.g., Cox & Bennett 1970;Hammer & Rostoker 1970;Berk & Pearlstein 1976).…”

Section: Zero Order System Statementioning

confidence: 99%

Influence of the Backreaction of Streaming Cosmic Rays on Magnetic Field Generation and Thermal Instability

Nekrasov

Shadmehri

2014

ApJ

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Using a multi-fluid approach, we investigate streaming and thermal instabilities of the electron-ion plasma with homogeneous cold cosmic rays propagating perpendicular to the background magnetic field. Perturbations are considered to be also across the magnetic field. The back-reaction of cosmic rays resulting in strong streaming instabilities is taken into account. It is shown that for sufficiently short wavelength perturbations, the growth rates can exceed the growth rate of cosmic-ray streaming instability along the magnetic field found by Nekrasov & Shadmehri (2012), which is in its turn considerably larger than the growth rate of the Bell instability (2004). The thermal instability is shown not to be subject to the action of cosmic rays in the model under consideration. The dispersion relation for the thermal instability has been derived which includes sound velocities of plasma and cosmic rays, Alfvén and cosmic-ray streaming velocities. The relation between these parameters determines the kind of thermal instability ranging from the Parker (1953) to the Field (1965) instabilities. The results obtained can be useful for a more detailed

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“…In these applications, the required lifetime of the beam is relatively short, and the most efficient process for its production is by field emission using an electrical transmission line for initial electrical energy storage. Many such field-emission-diode sources have been constructed capable of producing currents of several hundred kiloamperes for several tens of nanoseconds at potentials up to about 10MV (Ford et al 1967, Graybill and Nablo 1967, Grundhauser et al 1967, Roberts and Bennett 1968. Usually the electrode geometry and anode voltage of the diode are chosen such that the current is completely space-charge-limited.…”

Section: Introductionmentioning

confidence: 99%

Global Description of the Micro-Discharge System in Connection with the Plasma Display Panel

Uhm

Choi

Kim

2002

Jpn. J. Appl. Phys.

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Field emission in a plane-parallel electrode geometry at energies up to the relativistic regime is considered with the inclusion of finite velocity of electron emission from the cathode surface. The effect of this velocity is subsequently shown to be negligible. A technique is developed for evaluating the anode current/voltage/electrodespacing characteristics for any cathode material, from which the electrical impedance of the diode can be calculated. The completely space-charge-limited case is of particular interest, and a criterion is established that imposes an upper limit on the cathode workfunction in order that a particular diode should be at least 90% space-chargelimited. Fulfilment of this criterion implies that the diode current and impedance are determined, to 5 % accuracy, solely by the anode voltage, electrode spacing and cathode area. Consideration is also given to the transition from the field-emission discharge to the vacuum arc and another criterion imposed on the cathode material in order that this transition should not occur. Finally the bearing of this analysis on field emission in nonplanar geometries is considered.

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The pinch effect in pulsed streams at relativistic energies

Cited by 43 publications

References 2 publications

Back-reaction instabilities of relativistic cosmic rays

Back-reaction instabilities of relativistic cosmic rays

Influence of the Backreaction of Streaming Cosmic Rays on Magnetic Field Generation and Thermal Instability

Global Description of the Micro-Discharge System in Connection with the Plasma Display Panel

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