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
Filter
  • American Institute of Physics (AIP)  (9,667)
  • 2020-2020
  • 1995-1999  (9,667)
  • 1940-1944
  • 1995  (9,667)
Collection
Publisher
Years
  • 2020-2020
  • 1995-1999  (9,667)
  • 1940-1944
Year
  • 1
    Electronic Resource
    Electronic Resource
    Effect of aspect ratio on magnetic field fluctuations in the reversed-field pinch (1995)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 2 (1995), S. 3407-3411 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The effect of aspect ratio on magnetic field fluctuations in reversed-field pinches is investigated using a three-dimensional magnetohydrodynamic code. Configurations with aspect ratios of 1.1, 2.2, and 4.4 are modeled. The results are extrapolated to aspect ratio 8.8 for comparison with the Extrap T1 experiment [Nucl. Fusion 34, 427 (1994)]. It is found that the average modal amplitudes decrease with aspect ratio. However, the spectrum broadens correspondingly, resulting in negligible effect on the magnetic fluctuation level. The computed spectrum dynamics are found to be in good agreement with experimental observations on the T1 experiment. Quantitative evaluations of the field line stochasticity indicate no dependence of the mean magnetic field diffusion rate on aspect ratio. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871122
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Studies of impurity mode and ion temperature gradient mode in toroidal plasmas (1995)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 2 (1995), S. 3412-3419 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The impurity mode and ηi mode driven by impurity ions with outwardly peaked density profiles, near the boundary of tokamak plasmas, and the ion temperature gradient, respectively, are studied in high-temperature toroidal plasmas. The gyrokinetic theory is applied and finite Larmor radius effects of both hydrogenic and impurity ions are included. It is found that the impurity mode is enhanced by the ion temperature gradient. In addition, the impurity ions with outwardly peaked density profiles are demonstrated to have destabilizing effects on the ηi mode. These two modes are strongly coupled to each other so that it is impossible to distinguish between them when both the driving mechanisms are strong enough to drive the corresponding mode unstable independently. The correlation of the results with nonlinear simulations and the experimental observations are discussed. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871123
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Current and vorticity dynamics in three-dimensional magnetohydrodynamic turbulence (1995)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 2 (1995), S. 2931-2939 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Spectral numerical simulations of homogeneous incompressible magnetohydrodynamic turbulence at Reynolds mumbers up to about 500, are performed using a uniform grid of 1803 collocation points. Strong vorticity and current sheets obtain both in the presence and in the absence of magnetic nulls. Contrary to vortex sheets in hydrodynamics, these structures do not destabilize into filaments, but are locally disrupted. They are the main loci of kinetic and magnetic dissipations. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871473
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Broadband density fluctuation measurements using a heavy ion beam probe on the Texas Experimental Tokamak (1995)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 2 (1995), S. 3360-3367 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Broad bandwidth (60 kHz ≤f≤500 kHz), long wavelength (k¯θ≤2 cm−1) density fluctuation measurements were made using a heavy ion beam probe on the Texas Experimental Tokamak (TEXT) [K. W. Gentle, Nucl. Technol./Fusion 1, 479 (1981)]. Fluctuation amplitudes and correlation length scalings do not correspond to linear or quasilinear drift wave theory. Power-weighted root-mean-square (rms) wave number estimates are much lower (〈k¯θ〉rmsρs≤0.1, ρs=[miTe]1/2/eB) than quasilinear theoretical expectations (k¯⊥ρs∼0.3). Core results indicate strong turbulence with a wave number spread, Δk∼k¯ at fixed frequency f, consistent with strong turbulence predictions, while edge results can be considered consistent with weak turbulence. In between the core and edge (0.6≤r/a≤0.8) is a transition region. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871170
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    More on core-localized toroidal Alfvén eigenmodes (1995)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 2 (1995), S. 3401-3406 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A novel type of ideal toroidal Alfvén eigenmode, localized in the low-shear core region of a tokamak plasma, is shown to exist, whose frequency is near the upper continuum of the toroidal Alfvén gap. This mode converts to a kinetic-type toroidal Alfvén eigenmode above a critical threshold that depends on aspect ratio, pressure gradient, and shear. Opposite to the usual ideal toroidal Alfvén eigenmode, this new mode is peaked in amplitude on the small-major-radius side of the plasma. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871174
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Ponderomotive feedback stabilization of external kinks and disruptions in tokamaks (1995)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 2 (1995), S. 3429-3439 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A novel mechanism for feedback stabilization of external kink modes and disruptions is proposed in which modulated radio-frequency (RF) antennas apply a stabilizing ponderomotive force (PF) to the plasma. The RF power required for n=1 kink stabilization in the Princeton Beta Experiment-Modified (PBX-M) [Phys. Fluids B 2, 1271 (1990)] is estimated, and it is shown that the idea can be tested with the existing antenna system. A simulation of a preliminary n=0 modulation experiment on PBX-M also shows that the PF can balance applied vertical field oscillations. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871448
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Dynamics and stability of a stagnating hot spot (1995)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 2 (1995), S. 3466-3472 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A simple model of a hot spot implosion is developed, where the key parameters are the areal density ρsRs, the central temperature Ts, and the implosion velocity v∞. The dynamics is dominated by the mechanical compressing work and the thermal conduction loss. A new type of self-similar solution is then found, describing the fluid motion in terms of ρsRs/T2s and v∞/(square root of)Ts. A scaling law for the minimum implosion velocity v∞* to reach the spark point (ρsRs,Ts) is derived: v∞*∝Ts5/2/ρsRs. The Rayleigh–Taylor (RT) instability in the stagnation phase is evaluated using the self-consistent spatial profile with density gradients, which is attributed to the thermal conduction. Substantial reduction of the RT growth is then found compared with the previous work without density gradients [Hattori et al., Phys. Fluids 29, 1719 (1986)]. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871128
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Theory of relativistic gyro-traveling wave devices (1995)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 2 (1995), S. 3494-3510 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Using a Hamiltonian formalism, nonlinear, fully relativistic, multimode, multifrequency equations are derived which describe gyro-traveling wave devices. Nonuniform waveguides and nonlinearly tapered magnetic fields are incorporated into the analysis. The formalism is used to analyze the effect of velocity spread on Doppler upshifted operation. It is shown that with present technology, gyro-traveling wave devices cannot operate far from cutoff if high efficiency is desired. As an example, the analysis is applied to a 10 GHz, 430 kV, 240 A gyrotwistron operating at the fundamental cyclotron harmonic with a tapered wall radius and magnetic field. A realistic design that achieves over 30% efficiency is produced. The issue of stability of this device with respect to competition from parasitic modes is taken up in a companion paper [Phys. Plasmas 2, 3511 (1995)]. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871131
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Current drive due to fluid helicity (1995)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 2 (1995), S. 3539-3540 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The discrepancy in the expression for quasi-linear ponderomotive force as obtained by Klima and Petrazilka [Czech. J. Phys. B 30, 1002 (1980)] and by Fukuyama et al. [Phys. Fluids B 5, 539 (1993)] are resolved by showing that the extra terms in the expression of Klima and Petrazilka are due to fluid helicity of the fluctuations. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871135
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Anomalous pinch flux in tokamaks driven by the longitudinal adiabatic invariant (1995)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 2 (1995), S. 2874-2876 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The turbulent particle flux in tokamaks has an inward component, the pinch flux, which is independent of the density gradient. It is proposed that this flux represents a tendency of the particle distribution to approach turbulent equipartition, which means that the phase space density is constant on hypersurfaces defined by those invariants that are not destroyed by the turbulence. For tokamaks the two first adiabatic invariants give the peaked density profile n∼1/q of trapped particles. Sharp gradients are predicted near the separatrix of divertor plasmas. The physical mechanism of the pinch is as follows. When a parcel of trapped particles is displaced inward by the turbulent fluctuations, their parallel velocity must increase in order to keep the longitudinal invariant J constant. This is equivalent to adiabatic compression, and increases the density. The turbulence is assumed to be caused by thermally driven electrostatic modes. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871186
    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...