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Title: Defocusing of an ion beam propagating in background plasma due to two-stream instability

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Sponsoring Org.:
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Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 22; Journal Issue: 4; Related Information: CHORUS Timestamp: 2016-12-26 04:42:57; Journal ID: ISSN 1070-664X
American Institute of Physics
Country of Publication:
United States

Citation Formats

Tokluoglu, Erinc, and Kaganovich, Igor D. Defocusing of an ion beam propagating in background plasma due to two-stream instability. United States: N. p., 2015. Web. doi:10.1063/1.4917245.
Tokluoglu, Erinc, & Kaganovich, Igor D. Defocusing of an ion beam propagating in background plasma due to two-stream instability. United States. doi:10.1063/1.4917245.
Tokluoglu, Erinc, and Kaganovich, Igor D. 2015. "Defocusing of an ion beam propagating in background plasma due to two-stream instability". United States. doi:10.1063/1.4917245.
title = {Defocusing of an ion beam propagating in background plasma due to two-stream instability},
author = {Tokluoglu, Erinc and Kaganovich, Igor D.},
abstractNote = {},
doi = {10.1063/1.4917245},
journal = {Physics of Plasmas},
number = 4,
volume = 22,
place = {United States},
year = 2015,
month = 4

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1063/1.4917245

Citation Metrics:
Cited by: 8works
Citation information provided by
Web of Science

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  • The current and charge neutralization of charged particle beams by background plasma enable ballistic beam propagation and have a wide range of applications in inertial fusion and high energy density physics. However, the beam-plasma interaction can result in the development of collective instabilities that may have deleterious effects on ballistic propagation of an ion beam. In the case of fast, light-ion beams, non-linear fields created by instabilities can lead to significant defocusing of the beam. We study an ion beam pulse propagating in a background plasma, which is subjected to two-stream instability between the beam ions and plasma electrons, usingmore » PIC code LSP. The defocusing effects of the instability on the beam can be much more pronounced in small radius beams. We show through simulations that a beamlet produced from an ion beam passed through an aperture can be used as a diagnostic tool to identify the presence of the two-stream instability and quantify its defocusing effects. The effect can be observed on the Neutralized Drift Compression Experiment-II facility by measuring the spot size of the extracted beamlet propagating through several meters of plasma.« less
  • Cited by 4
  • Our paper presents a study of the two-stream instability of an electron beam propagating in a finite-size plasma placed between two electrodes. It is shown that the growth rate in such a system is much smaller than that of an infinite plasma or a finite size plasma with periodic boundary conditions. Even if the width of the plasma matches the resonance condition for a standing wave, a spatially growing wave is excited instead with the growth rate small compared to that of the standing wave in a periodic system. Furthermore, the approximate expression for this growth rate is γ≈(1/13)ω pe(nmore » b/n p)(Lω pe/v b)ln(Lω pe/v b)[1-0.18 cos (Lω pe/v b+π/2)], where ωpe is the electron plasma frequency, n b and n p are the beam and the plasma densities, respectively, v b is the beam velocity, and L is the plasma width. The frequency, wave number, and the spatial and temporal growth rates, as functions of the plasma size, exhibit band structure. Finally, the amplitude of saturation of the instability depends on the system length, not on the beam current. For short systems, the amplitude may exceed values predicted for infinite plasmas by more than an order of magnitude.« less
  • Collective Thomson scattering experiments reveal the presence of high-frequency, axial electron density fluctuations at millimetric wavelengths in the Hall thruster plasma. The properties of these fluctuations are investigated experimentally and via linear kinetic theory. The relative drift of electrons and ions in the axial direction is found to be insufficient to cause excitation of the observed mode. Instead, the mode is determined to be a two-stream instability arising due to the velocity difference between singly and doubly charged ion populations in the plume.