Library

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
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 7 (2000), S. 2894-2897 
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Positive voltage spikes caused by a fast decrease of the plasma current are observed in runaway dominated discharges in the small Brazilian Tokamak TBR-1[Kuznetsov et al., Phys. Plasmas 6, 4002 (1999)]. Comparison of the measured voltage spike with the value given by the solution of the one-dimensional diffusion equation for the toroidal electric field permits one to infer the plasma conductivity and initial electric field distribution. An additional runaway generation due to voltage spikes can be important. In this case, both the decay time of the voltage spike and the total toroidal current perturbation can decrease substantially. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 5 (1998), S. 3358-3365 
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The plasma rotation is theoretically investigated in toroidal devices. The dependence of magnetic axis curvature and torsion on the longitudinal coordinate and magnetic field ripples are taken into account. The calculations are carried out within the large aspect ratio and circular magnetic surfaces approximation. General equations for the relaxation of poloidal and toroidal velocities are obtained. The analysis of these equations is completed for the strongly collisional regime (the Pfirsch–Schlüter regime). It is shown that, as a result of the relaxation due to the ion parallel viscosity, there is an equilibrium with the ion toroidal velocity equal to zero. The general expression for the ion poloidal velocity in the Pfirsch–Schlüter regime is obtained. As in the tokamak case, this velocity is proportional to the ion temperature gradient. It does not depend on the plasma density gradient and on the radial electric field. The problems considered in the paper are of interest, specifically for toroidal devices of the "Drakon" ("Dragon") kind [V. M. Glagolev et al., in Proceedings of the X European Conference on Controlled Fusion and Plasma Physics, USSR, Moscow (European Physical Society, Petit-Lancy, 1981), Vol. 1, p. E8]. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The suppression of anomalous transport and/or reduction of neoclassical transport caused by the Alfvén-wave-induced shear of the radial electric field in tokamaks is investigated. The simple quantitative estimates reported in previous papers are checked by a consistent evaluation of the profile of the radial electric field created by the resonant absorption of Alfvén waves. The radial variations of the ion viscosity and heat conductivity across the mode conversion layer are evaluated both in the banana and potato regions. In agreement with previous analytical results, it is shown that the kinetic Alfvén waves may play the role of a convenient mechanism for reduction of anomalous and neoclassical transport and formation of transport barriers in tokamaks. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 7 (2000), S. 1060-1063 
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A new type of radio-frequency (rf) current drive in tokamaks is considered in this paper. The basic physical mechanism is connected with the dependence of the ion and electron viscosities on the time-averaged rf wave intensity. The new terms appear in the surface-averaged Ohm's law via the electron viscosity. Therefore, it is a bootstrap-like mechanism of rf current drive, not yet considered for tokamaks. At some special conditions, this type of the current drive can overcome the conventional one. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 6 (1999), S. 1378-1381 
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: General expressions for time- and surface-averaged radio frequency forces, affecting ions in closed toroidal devices, are obtained in this paper. Toroidal effects are included in these forces. These effects can, for example, be important to calculate Alfvén or fast wave forces in stellarators, spheromaks, or for toroidicity induced Alfvén wave eigenmodes (TAE) in axially symmetric tokamaks. The further simplification of obtained expressions should be fulfilled for the proper kind of rf waves and toroidal devices. It is hoped that these rf force expressions can, for example, be useful for the computer simulations of the transport barrier formation by Alfvén and fast waves in toroidal devices. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 4 (1997), S. 3436-3438 
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Dust particles appear on the edge of tokamak plasmas as a result of disruptions and plasma interactions with divertor plates, limiters, or blankets, as well as of pellet injections. It is shown that the presence of the dust impurities can lead to an effective decrease of the slow Alfvén wave absorption in the region. These waves are used for heating, current drive, and control of the low-to-high (L–H) confinement transition. Radio-frequency forces can also be strongly changed in the presence of dust particles. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 4 (1997), S. 3635-3643 
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The general approach to the Alfvén wave current drive problem in tokamaks with elongated transverse cross-sections was considered in this paper. Model approximations are used to describe circulating and trapped particle dynamics. This approach gives the accuracy of some percents. The expressions for the time-averaged longitudinal current and the radio-frequency currents have been obtained. They are supposed to be useful for a further analytical and computational solution of this problem. As an example, kinetic Alfvén waves are considered in this paper. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 2 (1995), S. 2784-2789 
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In this paper, general aspects of the Alfvén and fast wave nonresonant and resonant current-drive problem are considered both for collisional and weakly collisional plasmas. The magnetohydrodynamic approach is used for all collisional regimes and Landau damping is taken into account in the weakly collisional plasma case. Averaged in time and over magnetic surface, the general form of current-drive forces are derived, including the viscosity and collision frequency perturbation terms. As an example, a weakly collisional plasma cylinder case is discussed and some disagreements on this problem between different authors results are eliminated. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 5 (1998), S. 7-9 
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: It is demonstrated that Alfvén waves may be the convenient trigger for the formation of transport barriers in tokamaks. Kinetic or slow Alfvén waves, which appear in the tokamak plasma as a result of the rf wave's conversion, have small radial localizations. It is proposed that these waves can be used to create strongly sheared plasma flows at any point of the plasma minor radius, to suppress the plasma turbulence and to obtain the locally reversed magnetic shear configuration. Estimations concerning the absorbed power of Alfvén waves, which are necessary to suppress the plasma turbulence in some tokamaks, are about the level of absorbed power to be used in early fulfilled experiments. This method can assist the achievement of self-organization processes in tokamaks. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 3 (1996), S. 2818-2820 
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The effect of radio frequency fields on a plasma rotation in the edge (collisional) region of slightly rippled tokamaks is considered. The expressions for poloidal and toroidal velocities and for quasistationary radial electric fields are obtained as a function of absorbed rf power. The estimations of these quantities for the Phaedrus-T tokamak [N. Hershkovitz et al., 15th International Atomic Energy Agency Conference on Plasma Physics and Controlled Fusion, Seville, 1994 (International Atomic Energy Agency, Vienna, in press)] are also presented. It is shown that Alfvén waves can strongly modify the rotation velocities and radial electric fields in collisional regions of tokamak plasmas. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...