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
  • Articles  (251)
  • Wiley-Blackwell  (201)
  • American Institute of Physics (AIP)  (50)
Collection
  • Articles  (251)
Source
Keywords
Publisher
Years
Journal
Topic
  • 1
    Electronic Resource
    Electronic Resource
    Microwave/millimeter-wave generation in a counterstreaming-beam-plasma system (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 3057-3060 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Radiation from 8 to 60 GHz is generated by injecting counterstreaming, high-power (up to 50 keV and 4 A) electron beams into an unmagnetized, plasma-loaded waveguide. The radiation is emitted at twice the plasma frequency and is amplitude modulated on the ion plasma frequency time scale. The beam-to-millimeter-wave power conversion efficiency at 31 GHz is (approximately-greater-than)0.04%. A turbulence theory model is consistent with the radiation characteristics and power scalings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.354621
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    On the modification of the Kondorsky function (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 3184-3187 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The validity of Kondorsky's switching field distribution for pinning magnets with rectangular hysteresis loops is extended to cases where the hysteresis loops are influenced by reversible rotation of the magnetization vectors in the domains. Caused by this influence, the monotonic Kondorsky function changes to modified Kondorsky functions HP(cursive-theta0) with minimal switching fields for orientation angles cursive-theta0(approximately-greater-than)0° when HP(cursive-theta0 = 0°) reaches the anisotropy field strength Ha. It is shown that the modified Kondorsky function is a more suitable description of experimental results in the literature than the Kondorsky function itself.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.349301
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    A new method to determine the switching field distribution with application to barium ferrite powder (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 2465-2470 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A method to determine the switching field distribution Hs((large-closed-square)cr〉gc0) of powder assemblies of magnetically hard materials with a random orientation of the easy axes is described. The method is based on the ferromagnetic resonance absorption and the measurements of remanence curves. Direct information about the switching field distribution is obtained from major and minor loops of the hysteresis of the microwave absorption loss. By fitting calculated remanence curves and measured remanence curves the switching field distribution and its distribution at each orientation angle (large-closed-square)cr〉gc0 is obtained. The application of this method leads to switching field distributions for coprecipitated barium ferrite, which are strongly correlated to the predictions of the theory of coherent rotation. The distribution of Hs for this sample is made narrower by an etching process or by magnetic dilution. For barium ferrite prepared by the conventional oxid ceramic method with additional milling, a monotonic increase of the switching field with increasing orientation angle is found. This increase is much smoother than the Kondorsky function provides.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.348683
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Three-dimensional spontaneous magnetic reconnection in neutral current sheets (2000)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 7 (2000), S. 108-121 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Magnetic reconnection in an antiparallel uniform Harris current sheet equilibrium, which is initially perturbed by a region of enhanced resistivity limited in all three dimensions, is investigated through compressible magnetohydrodynamic simulations. Variable resistivity, coupled to the dynamics of the plasma by an electron–ion drift velocity criterion, is used during the evolution. A phase of magnetic reconnection amplifying with time and leading to eruptive energy release is triggered only if the initial perturbation is strongly elongated in the direction of current flow or if the threshold for the onset of anomalous resistivity is significantly lower than in the corresponding two-dimensional case. A Petschek-like configuration is then built up for ∼102 Alfvén times, but remains localized in the third dimension. Subsequently, a change of topology to an O-line at the center of the system ("secondary tearing") occurs. This leads to enhanced and time-variable reconnection, to a second pair of outflow jets directed along the O-line, and to expansion of the reconnection process into the third dimension. High parallel current density components are created mainly near the region of enhanced resistivity. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.873786
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Coalescence of magnetic islands including anomalous resistivity (1997)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 4 (1997), S. 3533-3543 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Two-dimensional compressible magnetohydrodynamic simulations of the coalescence instability in a low-beta plasma are presented in which anomalous resistivity is permitted to occur. The instability is considered in a uniform current sheet configuration, initially perturbed by an infinite chain of spots of anomalous resistivity. The two phases of the instability known from simulations based on the Fadeev equilibrium—ideal and resistive—can clearly be distinguished also in this configuration. It is found that the conversion of magnetic energy into kinetic energy dominates Ohmic heating. The main energy release occurs within a few Alfvén transit times. The scaling of several key parameters in the current layer formed between the coalescing islands is compared to the scalings obtained with uniform resistivity. The numerical results indicate that the peak reconnection rate decreases toward large Lundquist numbers (S(very-much-greater-than)104) as S−α with α=〈fraction SHAPE="CASE"〉15–〈fraction SHAPE="CASE"〉13 and that a transition to slow reconnection (α∼〈fraction SHAPE="CASE"〉12) may occur at S(approximately-greater-than)107, where S is based on the background resistivity. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.872250
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The transient behaviour of models of bowed-string motion (1995)
    Woodbury, NY : American Institute of Physics (AIP)
    Chaos 5 (1995), S. 509-523 
    Details
    ISSN: 1089-7682
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Theoretical models of the action of a bowed string may be able to shed light on differences of "playability'' between different violins. Subjective judgements seem to be concerned, at least in part, with the robustness with which one particular oscillation regime of the string (the "Helmholtz motion'') may be obtained under different bowing conditions. In this paper, after a review of bowed-string modelling, systematic simulation is used to obtain plots of the basin of attraction of the Helmholtz motion in a particular subspace of the player's control space. Variations in the size and structure of this basin of attraction are seen when parameters of the problem are varied, and some physical interpretation of these variations is given. Some parallels and contrasts are pointed out between the particular features of the bowed string as a nonlinear system, and the range of more familiar dynamical systems. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.166122
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Double-crystal x-ray spectroscopy at JET (1991)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 62 (1991), S. 889-898 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A double-crystal monochromator has been brought into operation at JET to measure absolute wavelengths and intensities of impurity spectral lines in the soft x-ray region from about 0.1 to 2.3 nm. It is capable of operating also during the deuterium-tritium (active) phase of JET because its detector is very effectively shielded against neutrons and hard x rays. The spectrometer has been swept over a wide wavelength range, around characteristic line groups as well as monochromatic line scans.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1142026
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Bragg spectroscopy of impurities during the JET preliminary tritium experiment : Proceedings of the 9th topical conference on high temperature plasma diagnostics (1992)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 63 (1992), S. 5023-5025 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Two Bragg spectrometers shared a shielded beamline, and monitored all significant plasma impurities throughout the Joint European Torus (JET) preliminary tritium experiment. The JET Active Phase Double Crystal Monochromator and a Bragg rotor spectrometer together monitored K-shell lines of Be, C, O, and Cl, and L-shell lines from metals such as Ni and Zn, in the wavelength range 0.2–11 nm. Background radiation was recorded during and after discharges, to assess the signal-to-noise ratio, and to monitor any activation or tritium ingress. Bragg spectroscopy was shown to be suitable for all impurities in magnetically confined D–T plasmas, using a thin foil to isolate tritium, and a low f-number shielded beamline. Future improvements to the signal-to-noise ratio are discussed in the context of a next-step machine such as ITER.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1143480
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Magnetic field correlations in kinematic two-dimensional magnetohydrodynamic turbulence (1999)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 6 (1999), S. 3477-3483 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The scaling properties of the second order magnetic structure function D2(B)(r) and the corresponding magnetic correlation function C2(B)(r) are derived for two-dimensional magnetohydrodynamic turbulence in the kinematic regime where the ratio of kinetic energy to magnetic energy is much larger than one. In this regime the magnetic flux function ψ can be treated as a passive scalar advected in a two-dimensional turbulent flow. Its structure function D2(ψ)(r) and the one for the magnetic field D2(B)(r) are connected by an exact relation. We calculate D2(ψ)(r) and thus D2(B)(r) within geometric measure theory over a wide range of scales r and magnetic Prandtl numbers Prm. The magnetic field correlations follow a r−4/3-scaling law and show an anticorrelation at the beginning of the Batchelor regime indicative of the formation of strongly filamented current sheets. Differences to the full dynamic regime, where the ratio of kinetic to magnetic energies is smaller than in the kinematic case, are discussed. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.873609
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Dynamic current sheets with localized anomalous resistivity (1996)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 3 (1996), S. 4703-4711 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Two-dimensional compressible magnetohydrodynamic simulations of current sheet dynamics under the influence of localized anomalous resistivity are presented. The system is initially perturbed by several spots of anomalous resistivity distributed in the sheet. Following a phase of induced tearing resulting from the initial perturbation, magnetic island coalescence occurs until one island persists. Finally the evolution becomes eruptive, dominated by the acceleration and ejection of a plasmoid, as a consequence of the amplification of a small initial asymmetry after a few 102 Alfvén times. These processes are accompanied by strong enhancements of the current density. It exceeds the threshold of kinetic instability repeatedly and leads to recurrence of anomalous resistivity, which drives the evolution. Jets are formed, driven by field line reconnection and locally enhanced dissipation at dominant X-points. The conversion of magnetic energy into kinetic energy is most efficient during the acceleration phase of the plasmoid. The evolution becomes more impulsive and leads to stronger current density enhancements for higher Lundquist numbers. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.872037
    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...