摘要:

Lowm‐number fluctuations of floating potential, density, and magnetic fields have been investigated in Ohmically heated discharges in the C stellarator. The azimuthal velocity of the perturbations reverses direction nearvD/vi= 1 (vDis the electron drift velocity due to current andviis the ion thermal velocity). ForvD/vi≳ 1, the wave moves at about the electron diamagnetic drift velocity and detailed probe measurements are consistent with the mode being the current‐driven universal instability: the amplitude and relative phasing of the fluctuations indicate that the low‐mfluctuations can cause the plasma loss. ForvD/vi≲ 1, the wave moves close to the plasmaEr× B0velocity and measurements are consistent with the resistive‐gmode: measurement accuracy prevents a definite statement on the relationship between the fluctuations and the plasma loss.

ISSN:0031-9171    

DOI:10.1063/1.1761978

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

For a perfectly conducting plasma magnetized by a dipole field, the magnetohydrodynamic toroidal mode describes waves which propagate energy along the field lines. This characteristic causes the resonance oscillations of this mode to be strongly latitude‐dependent. The periods of these oscillations are determined for a generalized plasma density of the form &rgr; = &rgr;0(a/r)sD(&jgr;) and compared with previously obtained results for the poloidal or isotropic mode. A discussion is provided of the validity of the model plasmasphere and the conditions for experimental observation.

ISSN:0031-9171    

DOI:10.1063/1.1761979

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

The surface integral term resulting from application of Rosen's restricted variational principle to kinetic theory boundary value problems in a three‐dimensional physical space is shown to lead to a natural boundary condition equivalent to surface flux conservation.

ISSN:0031-9171    

DOI:10.1063/1.1761980

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

A series expansion for the second virial coefficient of the spherical shell potential is used to show that this model, in contrast to the Kihara model, does not inadvertently include terms which can represent contributions due to multipolar interactions.

ISSN:0031-9171    

DOI:10.1063/1.1761981

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

The discrete ordinate method for unsteady linearized Boltzmann Bhatnagar‐Gross‐Krook equation is established. For the simplest case whenn= 1, the result reduces immediately to that previously discussed by Broadwell for Rayleigh problem.

ISSN:0031-9171    

DOI:10.1063/1.1761982

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Flow around a nonconducting sphere moving slowly through a current‐carrying fluid along an arbitrary direction is considered. Standing eddies are found under certain conditions and a wake ahead of the sphere is possible.

ISSN:0031-9171    

DOI:10.1063/1.1761983

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

The stability of a bumpy &thgr; pinch is studied by assuming that the plasma and field are separated by a thin boundary and that the plasma is collisionless. The unstable modes have the largest displacement from equilibrium in the regions of ``bad'' surface curvature.

ISSN:0031-9171    

DOI:10.1063/1.1761984

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Modified quasi‐linear equations have been derived which predict that the particle velocity distribution function approaches the Maxwell‐Boltzmann distribution and the energy distribution of plasma oscillations approaches the Raleigh‐Jeans distribution.

ISSN:0031-9171    

DOI:10.1063/1.1761985

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

The perturbation of the potential distribution in collisionless plasmas by a weak magnetic field is calculated numerically by considering the effect of the field on the boundary condition at the insulating wall.

ISSN:0031-9171    

DOI:10.1063/1.1761986

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Equations are given for the time history of noise energy spectra, due to wave‐wave scattering of quasi‐longitudinal plasma oscillations for the case of a magnetoactive plasma with different electron and ion temperatures. An example of such a process is presented.

ISSN:0031-9171    

DOI:10.1063/1.1761988

出版商:AIP    

年代:1967

数据来源: AIP