ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Spatial distributions of trapped microparticles in a plasma sheath (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 3602-3605 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The density distributions of trapped microparticles under the interaction of electrostatic, gravitational, ion-drag, and pressure gradient forces in a cathode sheath are investigated in a self-consistent model. It is found that instead of a δ-function distribution for cold microdust particles, the distribution for the particles with a finite temperature has a thermal broadening throughout the trapping region. The region where the microparticles are trapped is wider for a higher dust temperature or a smaller particulate radius and much narrower for a much lower dust temperature or a bigger particulate radius. For a very low temperature, the distribution exhibits a sharp peak. The peak can shift from the edge into the sheath region as the particulate radius increases. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1345861
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Analysis of the effect of external gas flow on helical instabilities of arc plasmas (2001)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 8 (2001), S. 3833-3837 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The effect of external gas flow on helical instability of arcs is studied by using an analytical method. The magnetohydrodynamic equations in an electrostatic approximation serve as the starting point of the theory. Using a linear time-dependent perturbation theory, the analytic expression that corresponds to the term of a gas flow stabilizing effect is deduced, and the growth rate of the helical instability is given. It is found that in the short wavelength perturbation case, the effect of external gas flow is large, so it is beneficial for stabilizing arcs. However, its effect is very small for intermediate and long wavelength perturbations. At the same time, numerical results show that the stabilizing effect of the flow on helical instability increases with increasing shear viscosity of external gas flow. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1379343
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The electrostatic sheath in a dusty plasma (2000)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 7 (2000), S. 3093-3096 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The electrostatic sheath in a conventional dc discharge involving dusty plasmas is revisited. Assuming Boltzmann responses for electrons and dust particles and taking into account the effect of ion flows, it is shown that the sheath around an electrically floated cylindrical wire contains electrons and ions but no dust particles. The dust particle density rises sharply at the plasma-sheath interface, as seen in a recent experiment [C. O. Thompson, N. D'Angelo, and R. L. Merlino, Phys. Plasmas 6, 1421 (1999)]. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.874164
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    An electrostatic magnetohydrodynamics theory for resistive-viscous helical instabilities of arc discharges (1997)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 4 (1997), S. 2791-2797 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A simplified linear analysis for resistive-viscous magnetic helical instabilities of arc discharges in a cylindrical plasma is developed. Based on a set of electrostatic magnetohydrodynamic (MHD) equations, resistive-viscous m=1 modes with an external axial magnetic field are studied. Explicit analytic results are obtained, from which the growth rate and the stability criterion can be shown, and the electrostatic assumption can be justified. In comparison with the previous channel model calculations, this analytic treatment can provide a simplified model for instability estimates, while avoiding artificial assumptions and misorderings in the energy equation. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.872411
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Forced magnetic reconnection and the persistence of current sheets in static and rotating plasmas due to a sinusoidal boundary perturbation (1996)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 3 (1996), S. 2427-2433 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The problem of forced reconnection in static and rotating plasmas due to a sinusoidal boundary perturbation is revisited. The primary focus of this paper is on inner region dynamics, including the effects of resistivity as well as viscosity. It is shown that for high-Lundquist-number plasmas, the use of the "constant-ψ'' approximation in the linear and nonlinear regimes of forced reconnection is not justified. The linear and nonlinear dynamics in the inner region are characterized by the persistence of current sheets. Explicit analytical solutions for the time dependence of the reconnected flux and current sheet density are given, and tested by numerical simulations. These results differ qualitatively from earlier analytical results on forced reconnection in static plasmas [T. S. Hahm and R. M. Kulsrud, Phys. Fluids 28, 2412 (1985)] (except in a very restricted range of parameters) as well as rotating plasmas [R. Fitzpatrick and T. C. Hender, Phys. Fluids B 3, 644 (1991)]. Some qualitative implications for laboratory and space plasmas are discussed. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871927
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Fast magnetic reconnection and sudden enhancement of current sheets due to inward boundary flows (1996)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 3 (1996), S. 2129-2134 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Magnetic reconnection is widely believed to be involved in dynamical phenomena such as solar flares or magnetospheric substorms. The Sweet–Parker model of magnetic reconnection in a Y-type geometry predicts a characteristic time scale proportional to S1/2 (where S is the Lundquist number), which is too slow to account for the observed time scales. The Petschek model, in contrast, predicts a time scale proportional to ln S in an X-point geometry. Numerical magnetohydrodynamic (MHD) simulations in the high-S regime generally validate the Sweet–Parker model, unless the resistivity is enhanced in the diffusion region to large values (such that typically S〈103). It is demonstrated in this paper that nonlinear reconnection dynamics in a Harris sheet driven by inward boundary flows occurs on a nonlinear time scale that is proportional to S1/5 and thus has a weaker dependence on resistivity than the Sweet–Parker time scale. The current sheet amplitude at the separatrix (spanning Y points) grows algebraically in the linear regime but is suddenly enhanced after it makes a transition to the nonlinear regime. An analytical calculation is given for both the linear and the nonlinear regimes, and supported by two-dimensional resistive MHD simulations. The features of sudden current sheet enhancement and fast reconnection, controlled by boundary flows, are relevant to the phenomena of substorm onset or the impulsive phase of flares. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871665
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Tearing stability of the two-dimensional magnetotail (1995)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 2 (1995), S. 3857-3864 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The linearized incompressible magnetohydrodynamic equations that include a generalized Ohm's law are solved for tearing eigenmodes of a plasma sheet with a normal magnetic field (Bn). In contrast to the Harris sheet with the equilibrium magnetic field [B=B0 tanh(z/a)xˆ], the two-dimensional plasma sheet with the field [B=B0 tanh(z/a)xˆ+Bnzˆ], in which the Bn field lies in the plane of the Bx field, has no neutral line if Bn≠0. Such a geometry is intrinsically resilient to tearing because it cannot change topology by means of linear perturbations. This qualitative geometrical idea is supported by calculations of growth rates using a generalized Ohm's law that includes collisional resistivity and finite electron inertia as the mechanisms for breaking field lines. The presence of Bn reduces the resistive tearing mode growth rate by several orders of magnitude (assuming Bn/B0∼0.1) compared with that in the Harris sheet model (Bn=0). The growth rate scaling with Lundquist number (S) has the typical S−3/5 (S−1/3) dependence for large (small) wave numbers and very small values of Bn. For larger values of Bn, all modes behave diffusively, scaling as S−1. The collisionless electron tearing mode growth rate is found to be proportional to δ2e in the presence of significant Bn((approximately-greater-than)10−2B0) and large kx(∼0.1a−1–0.5a−1), and becomes completely stable (γ〈0) for Bn/B0≥0.2. Implications for magnetospheric substorms are discussed. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871085
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Exponential nonlinear growth of a resistive m=1 island (1999)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 6 (1999), S. 1674-1676 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: An analytical model is given for the exponential growth of a m=1 resistive island in the late nonlinear stage of its dynamics, observed in a recent numerical simulation [A. Aydemir, Phys. Rev. Lett. 78, 4406 (1997)]. This late nonlinear exponential growth phase follows the linear exponential growth phase and an early nonlinear algebraic growth phase. It is shown that the transition from the early nonlinear phase of algebraic growth in time to exponential growth occurs due to change in the geometric structure of the current sheet. Analytical predictions are in reasonable accord with simulation results. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.873424
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Dynamics of current sheet formation and reconnection in two-dimensional coronal loops (1995)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 2 (1995), S. 3184-3193 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Current sheet formation and magnetic reconnection in a two-dimensional coronal loop with an X-type neutral line are simulated numerically using compressible, resistive magnetohydrodynamic equations. Numerical results in the linear and nonlinear regimes are shown to be in good agreement with a recent analytical theory [X. Wang and A. Bhattacharjee, Astrophys. J. 420, 415 (1994)]. The topological constraint imposed by helicity-conserving reconnection is discussed. It is found numerically that helicity-conserving reconnection causes the initial X-point structure of the loop to change to Y points, with current sheets at the separatrices encompassing the Y points. Implications for observations are discussed. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871150
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Ionization instabilities and resonant acoustic modes (2001)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 8 (2001), S. 5018-5024 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A linear stability analysis of ion-acoustic and dust-acoustic waves is carried out using a multifluid model in the presence of ionization, ion drag, and collisions of ions and dust with the background neutral gas. It is found that an unstable dust-acoustic mode of nonzero real frequency can be generated via a resonance phenomenon. This resonance develops as the frequency of the dust-ion-acoustic mode is reduced sufficiently in the long-wavelength regime that it couples strongly to the dust-acoustic mode. As the charge on dust particles exceeds a threshold, multiple low-frequency modes with large growth rates are excited suddenly. Predictions of the theory are compared with experimental results [D. Samsonov and J. Goree, Phys. Rev. E 59, 1047 (1999)]. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1398283
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...