摘要:

The differences in the energy transport equations for tokamaks and stellarators associated with &Ggr;rErare discussed, where &Ggr;ris the radial particle flux andEris the radial electric field. The energy exchange quantities are evaluated in terms of poloidal plasma flow, pressure gradient, andEr. It is found that for stellarators the radial flux &Ggr;rin &Ggr;rErshould be &Ggr;r=&Ggr;na, the nonaxisymmetric flux, instead of the total particle flux.

ISSN:0031-9171    

DOI:10.1063/1.866758

出版商:AIP    

年代:1988

数据来源: AIP

摘要:

Stability of the thermodynamic equilibrium is put forward as a simple test of the validity of dynamic equations, and is applied to perpendicular gyroviscous magnetohydrodynamics (i.e., perpendicular magnetohydrodynamics with gyroviscosity added). This model turns out to be invalid because it predicts exponentially growing Alfve´n waves in a spatially homogeneous static equilibrium with scalar pressure.

ISSN:0031-9171    

DOI:10.1063/1.866759

出版商:AIP    

年代:1988

数据来源: AIP

摘要:

Large ponderomotive forces can occur near a high‐power ion cyclotron range of frequency antenna, particularly for the parallel electric field polarization used to excite ion‐Bernstein waves (IBW). The magnetohydrodynamic (MHD) equilibrium of the edge plasma is modified by these forces when the antenna is highly localized poloidally and toroidally. Magnetic islands develop at the edge, nearq=m/n, where ‖m‖≤&pgr;a/waand ‖n‖≤&pgr;R/la, withwaandlathe width and length of the antenna, respectively. Ergodicity of the magnetic field lines may be expected when the islands overlap. Numerical calculations of the island overlap criteria are presented for two examples relevant to present day (IBW) heating experiments.

ISSN:0031-9171    

DOI:10.1063/1.866760

出版商:AIP    

年代:1988

数据来源: AIP

摘要:

A simple derivation of the Langmuir wave growth rate in the presence of a coherent ion sound wave is shown, based on high‐frequency nonlinear force. The new energy up‐conversion process (plasma–maser) may play an important role in space and laboratory plasmas with enhanced low‐frequency fluctuations.

ISSN:0031-9171    

DOI:10.1063/1.866761

出版商:AIP    

年代:1988

数据来源: AIP

摘要:

An analytical expression for the ponderomotive force is derived in a system with a standing wave. The ponderomotive force first increases with the wave amplitude, then decreases and becomes zero at a certain value of the amplitude above which chaos is initiated. The result is confirmed by numerical experiments.

ISSN:0031-9171    

DOI:10.1063/1.866762

出版商:AIP    

年代:1988

数据来源: AIP

摘要:

A novel method has been proposed for indefinite nonstochastic acceleration of particles by electrostatic waves propagating normal to a magnetic field. Use is made of a magnetic field inhomogeneity to prevent the particle from detrapping from the electrostatic wave. Numerical plots of particle trajectories are presented.

ISSN:0031-9171    

DOI:10.1063/1.866763

出版商:AIP    

年代:1988

数据来源: AIP

摘要:

The generation of an axial magnetic field caused by the interaction of standing waves formed by two counterpropagating, elliptically polarized electromagnetic waves with a laser‐produced plasma has been investigated. Study of the variation of magnetization with different powers and wavelengths available from Nd–glass and CO2lasers shows that induced axial magnetization increases linearly with an increase in power for all wavelengths and increases exponentially with the wavelengths for different laser powers at a particular plasma density. The variation of magnetization with plasma density reveals that the peak value of magnetization occurs below the critical density (nc) for a particular wavelength and power. Scaling laws for the induced axial magnetic field have been given. The poloidal fields arising from such mechanisms are important in the lateral energy and axial energy transport mechanisms. Such a field inhibits lateral energy transport, but axial energy propagation may be increased.

ISSN:0031-9171    

DOI:10.1063/1.866764

出版商:AIP    

年代:1988

数据来源: AIP