GLORIA

GEOMAR Library Ocean Research Information Access

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
Document type
Publisher
Years
  • 1
    Electronic Resource
    Electronic Resource
    Measurements of the trapped particle sideband instability compared to the macroparticle model (2001)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 8 (2001), S. 3457-3466 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The upper and lower sidebands are measured on a traveling wave tube where a cold electron beam is trapped by a large amplitude wave. The two strongly coupled sidebands form a normal mode that is characterized by the sideband growth rates, wave number shifts, amplitude ratio, and phase relationship. The measured values agree only qualitatively with the macroparticle model of Kruer, Dawson, and Sudan [Phys. Rev. Lett. 23, 838 (1969)]. Also, the macroparticle model prediction for a nonlinear product wave does not agree with the experiment. Quantitative agreement is found between the experiment and computer simulations that follow the electron orbits, suggesting that the trapped particle model is too simple for quantitative predictions. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1379341
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Measurements of the weak warm beam instability (1995)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 2 (1995), S. 654-677 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Experiments are described on the interaction of a weak warm beam with a broad spectrum of unstable waves on a traveling wave tube. The wave–particle interactions are similar to those in beam–plasma systems, and are traditionally described by quasilinear theory. The precise wave evolution is obtained by launching a specified waveform, allowing it to interact with the beam, and analyzing the received waveform. Significant mode coupling is observed, resulting in saturated waves correlated less than 0.5 with their launch values. Experimentally, each wave is separated into a component proportional to the launch amplitude and a component due solely to mode coupling. The measured properties of these separate components agree quantitatively with a four-wave coupling model. Strongest coupling is observed between waves whose wave numbers match within about an inverse turbulent trapping length. In the linear growth regime, the measured ensemble-averaged wave growth rates and beam velocity diffusion rates agree reasonably with quasilinear and resonance-broadening theory; in the nonlinear regime near saturation, the discrepancies become larger. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871418
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Ion cyclotron range of frequency heating experiments on the large helical device and high energy ion behavior : The 42nd annual meeting of the division of plasma physics of the American Physical Society and the 10th international congress on plasma physics (2001)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 8 (2001), S. 2139-2147 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Ion cyclotron range of frequency (ICRF) heating experiments on the Large Helical Device (LHD) [O. Motojima et al. Fus. Eng. Des. 20, 3 (1993)] achieved significant advances during the third experimental campaign carried out in 1999. They showed significant results in two heating modes; these are modes of the ICH-sustained plasma with large plasma stored energy and the neutral beam injection (NBI) plasma under additional heating. A long-pulse operation of more than 1 minute was achieved at a level of 1 MW. The characteristics of the ICRF heated plasma are the same as those of the NBI heated plasma. The energy confinement time is longer than that of International Stellarator Scaling 95. Three keys to successful ICRF heating are as follows: (1) an increase in the magnetic field strength, (2) the employment of an inward shift of the magnetic axis, (3) the installation of actively cooled graphite plates along the divertor legs. Highly energetic protons accelerated by the ICRF electric field were experimentally observed in the energy range from 30 to 250 keV and the tail temperature depended on the energy balance between the wave heating and the electron drag. The transfer efficiency from the high energy ions to the bulk plasma was deduced from the increase in the energy confinement time due to the high energy ions in the lower density discharge, which agrees fairly well with the result obtained by the Monte Carlo simulation. The transfer efficiency is expected to be 95% at an electron density of more than ne=5.0×1019 m−3 even in the high power heating of 10 MW. The accumulation of impurities, e.g., FeXVI and OV was not observed in high rf power and long pulse operation. The well-defined divertor intrinsic to LHD is believed to be useful in reducing the impurity influx. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1354152
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    facet.materialart.
    Unknown
    Ultrafast electron diffraction from non-equilibrium phonons in femtosecond laser heated Au films (2016)
    American Institute of Physics (AIP)
    Details
    Publication Date: 2016-01-29
    Description: We use ultrafast electron diffraction to detect the temporal evolution of non-equilibrium phonons in femtosecond laser-excited ultrathin single-crystalline gold films. From the time-dependence of the Debye-Waller factor, we extract a 4.7 ps time-constant for the increase in mean-square atomic displacements. The observed increase in the diffuse scattering intensity demonstrates that the energy transfer from laser-heated electrons to phonon modes near the X and K points in the Au fcc Brillouin zone proceeds with timescales of 2.3 and 2.9 ps, respectively, faster than the Debye-Waller average mean-square displacement.
    Print ISSN: 0003-6951
    Electronic ISSN: 1077-3118
    Topics: Physics
    Published by American Institute of Physics (AIP)
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...