Behaviour of a plasma interacting with the counter-rotating high-frequency fields of a multipole configuration

The authors consider the interaction of a plasma column in a constant magnetic field Hz with a system of two counter-rotating high-frequency magnetic fields whose axis of rotation is directed along a constant magnetic field. Both the first and the second wave are uniform along the axis of rotation. The configuration of the high-frequency field is such that the electrical component of the field is directed along the constant magnetic field, while the latter does not influence the effectiveness of the action of the high-frequency field on the plasma.It is assumed that the collision frequency ν of the charged particles in the plasma is non-zero. Taking into account entrainment of the plasma by the high-frequency field, one can use — instead of the second wave of the alternating field — the constant magnetic field of a multipole configuration, which behaves as a high-frequency field relative to the rotating plasma. The distribution of the plasma rotation velocity vφ, the charged particle concentrations N and the strength of the alternating fields φ, and r along the plasma column radius are determined by a system of Maxwellian equations and equations of motion for the ions and electrons. A system of equations with boundary conditions is solved by computer, and the radial dependences of the angular velocity of rotation, the plasma concentration and the high-frequency fields for different values of the multipole magnetic field and the plasma concentration are ascertained. If the ratio of the field strengths at the plasma boundary is of the order of unity, then the plasma column has a tubular structure.In the case of a rotating plasma, the radial distribution of the high-frequency field is of a peculiar type.

日本語訳

著者らは、一定磁場Hz中のプラズマ柱と、その回転軸が一定磁場に沿って方向付けられた2つの逆回転高周波磁場の系との相互作用を考察する。第1波と第2波はともに回転軸に沿って一様である。高周波場の配位は、場の電気成分が一定磁場に沿って方向付けられるようなものであり、後者はプラズマに対する高周波場の作用の有効性に影響を与えない。プラズマ中の荷電粒子の衝突周波数νは非ゼロであると仮定される。高周波場によるプラズマの随伴を考慮すると、多重極配位の一定磁場を、回転プラズマに対して高周波場として振る舞う交番場の第2波の代わりに用いることができる。プラズマ回転速度vφの分布、荷電粒子濃度N、および交番場φとrの強度は、マクスウェル方程式系とイオンおよび電子の運動方程式によってプラズマ柱半径に沿って決定される。境界条件を伴う方程式系はコンピュータによって解かれ、角速度の動径依存性、プラズマ濃度、および多重極磁場とプラズマ濃度の異なる値に対する高周波場の動径依存性が確認される。プラズマ境界における場の強度比が1のオーダーである場合、プラズマ柱は管状構造を有する。回転プラズマの場合、高周波場の動径分布は特異なタイプを示す。