Nonlocal theory of the spectra of modified ion cyclotron oscillations in a charged plasma produced by gas ionization

Yeliseyev, Yu. N.

doi:10.1134/s1063780x06110079

Cited by 4 publications

(12 citation statements)

References 15 publications

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“…In the present work (unlike [1,2]) we assume, that the radial electric field is caused by a space charge of electrons and ions of plasma: -{2eImJE^ = cdp^{\-f)r {f = NJn^ is a factor of charge neutralization). Setting the goal to carry out the studying of plasma stability within the whole admissible range of radial electric field changing, we use the general expressions for frequencies co^ and Q^ in (8), valid at arbitrary strengths of radial electric fields, [5] 6> The last inequality in (9) determines the range of admissible values of parameter lofpe / ffi^^.…”

Section: Dispersion Equation Of Plasma Oscillationsmentioning

confidence: 99%

“…The non-local consideration of plasma stability is carried out in the same way as in [1,2]-by the joint solving of the Vlasov -Poisson equations. Plasma is held within a metal casing (anode) of the same radius a, as the radius of plasma.…”

Section: Dispersion Equation Of Plasma Oscillationsmentioning

confidence: 99%

“…The equilibrium distribution function of plasma electrons was chosen in [1,2] as a Maxwellian one "with a shift" equal to V^ = co/. It is the equilibrium of a «rigid rotator»-type [5].…”

Section: F(e^mv^) = ^^Y[e^{a)-e^)-s(e^-co"m)-s(v^)mentioning

confidence: 99%

“…The non-local studying of the stability of plasma cylinder, placed in crossed longitudinal magnetic (B) and radial electrical (E^<0) fields, was carried out in [1,2]. Running helical potential waves ^ = ^",(r)exp[i(mq)+k^z-ax)],…”

Section: Introductionmentioning

confidence: 99%

“…This peculiarity determinates uniquely the equilibrium distribution function of ions. Its form was found in [3,4] and was used in [1,2]:…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Stability of Non-Neutral Plasma Cylinder Consisting of Magnetized Cold Electrons and of Small Density Fraction of Ions Born at Rest: Non-Local Analysis

Yeliseyev¹

2009

AIP Conference Proceedings

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The non-local stability problem of the plasma cylinder, filled with "cold" magnetized rigidly rotating electrons, and a small density fraction of ions, is solved. The ions are supposed to be bom at rest by ionization of background gas. The study is based on the kinetic description of ions. The equilibrium distribution function, taking into account the peculiarity of ions birth, is used. The radial electric field is caused by space charge of non-neutral plasma. The dispersion equation for plasma eigen frequencies is obtained analytically. It is valid within the total admissible range of values of electric and magnetic fields. Normahzed eigen frequencies of / Q.. are calculated for the basic azimuth mode m = 1 (o' = o-rno*, ffli^ = (-ffli,;+0;)/2 , Q.. ={m^.-AeE^ Im.rj is called the "modified" ion cyclotron (MIC) frequency), for the density fraction of ions of atomic nitrogen / = Af / n = o, 01 and are presented in graphic form versus parameter 2ffl\/ft/. The spectra of osciUations o'/O,. consist of the family of electron Trivelpiece -Gould (TG) modes and of the families of MIC modes. The frequencies of MIC modes are located in a small vicinity of harmonics of the MIC frequency Q. above and below the harmonic. The TG modes in non-neutral plasma fall in the region of MIC frequencies O,. and interact strongly with MIC modes. The slow TG modes become unstable near the crossings with nonnegative harmonics of MIC frequencies. The instabilities have a resonant character. The lowest radial TG mode has a maximum growth rate at crossing with a zero harmonic of O,. ((Imo'/O;)jjj^ = 0,074). The growth rates of MIC modes are much lower ((Imco'/ Q..)^^ < 0,002). Their instability has a threshold character. The instabilities of TG and MIC modes take place mainly at the values of parameter 2ffl\ / wl, corresponding to strong radial electric fields (ffii,/ «\eE^ / m/\), in which the ions are unmagnetized. The oscillations of small amplitude are seen on some frequency dependencies of MIC modes. They are similar to oscillations on dispersion curves of electron waves in metals and are caused by the similarity between the ion equihbrium distribution function and the degenerate Fermi -Dirac one. The results obtained give the solution to the stability problem discussed by R.H. Levy, J.D. Daugherty and O. Buneman[ Phys. Fl. 12, 2616 -2629(1969] for a special case of plasma bounding directly with metal casing and possessing the volumetric eigen modes only.

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Section: Dispersion Equation Of Plasma Oscillationsmentioning

confidence: 99%

Section: Dispersion Equation Of Plasma Oscillationsmentioning

confidence: 99%

“…The equilibrium distribution function of plasma electrons was chosen in [1,2] as a Maxwellian one "with a shift" equal to V^ = co/. It is the equilibrium of a «rigid rotator»-type [5].…”

Section: F(e^mv^) = ^^Y[e^{a)-e^)-s(e^-co"m)-s(v^)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…This peculiarity determinates uniquely the equilibrium distribution function of ions. Its form was found in [3,4] and was used in [1,2]:…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Stability of Non-Neutral Plasma Cylinder Consisting of Magnetized Cold Electrons and of Small Density Fraction of Ions Born at Rest: Non-Local Analysis

Yeliseyev¹

2009

AIP Conference Proceedings

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Trivelpiece–Gould modes and low-frequency electron–ion instability of non-neutral plasma

Yeliseyev

2024

J. Plasma Phys.

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The frequency spectra of the Trivelpiece–Gould modes of a waveguide partially filled with non-neutral plasma are determined numerically by solving the dispersion equation. The modes having azimuthal number $m = 1$ are considered. The results are presented for the entire acceptable range of electron densities, magnetic field strengths, for different values of the charge neutralization coefficient. The Cherenkov resonance condition of an ion with a diocotron mode having a finite value of the longitudinal wave vector was studied. The characteristics of resonant low-frequency electron–ion instability caused by relative azimuth motion of electrons and ions in crossed fields and by the anisotropy of the distribution function of ions are discussed. Ions are created by ionization of residual gas in the plasma volume. Due to the anisotropy, instability occurs not only in the vicinity of the resonance, but also outside it. For typical values of plasma parameters in experiments, estimations of the frequency growth rate are given. A conclusion is drawn that this instability can be the cause of the low-frequency oscillations observed in linear devices with non-neutral plasma produced in an electron beam channel.

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Ion velocity analysis of rotating structures in a magnetic linear plasma device

et al. 2018

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The MISTRAL device is designed to produce a linear magnetized plasma column. It has been used a few years ago to study a nonlinear low frequency instability exhibiting an azimuthal number m = 2. By changing the experimental configuration of MISTRAL, this work shows experimental results on an m = 1 rotating instability with strongly different behavior. The spatio-temporal evolution of the ion velocity distribution function given by a laser-induced fluorescence diagnostic is measured to infer the radial and azimuthal velocities, ion fluxes, and electric fields. The naive image of a plasma exhibiting a global rotation is again invalidated in this m = 1 mode but in a different way. Contrary to the m = 2 mode, the rotation frequency of the instability is lower than the ion cyclotron frequency and ions exhibit a complex behavior with a radial outward flux inside the unstable arm and azimuthal ion fluxes always directed toward the unstable arm. The azimuthal ion velocity is close to zero inside the ionization region, whereas the radial ion velocity grows linearly with radius. The radial electric field is oriented inward inside the unstable arm and outward outside. An axial velocity perturbation is also present, indicating that contrary to the m = 2 mode, the m = 1 mode is not a flute mode. These results cannot be easily interpreted with existing theories.

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Nonlocal theory of the spectra of modified ion cyclotron oscillations in a charged plasma produced by gas ionization

Cited by 4 publications

References 15 publications

Stability of Non-Neutral Plasma Cylinder Consisting of Magnetized Cold Electrons and of Small Density Fraction of Ions Born at Rest: Non-Local Analysis

Stability of Non-Neutral Plasma Cylinder Consisting of Magnetized Cold Electrons and of Small Density Fraction of Ions Born at Rest: Non-Local Analysis

Trivelpiece–Gould modes and low-frequency electron–ion instability of non-neutral plasma

Ion velocity analysis of rotating structures in a magnetic linear plasma device

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