Formation of Viscous Vortex and Anomalous Viscosity in a Plasma

等离子体中粘性涡旋和反常粘度的形成

• 批准号: 15340202
• 负责人: TANAKA Masayoshi
• 金额: $ 10.3万
• 依托单位: KYUSHU UNIVERSITY (2005)National Institute for Fusion Science (2003-2004)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15340202/
• 关键词: vortex; anomalous viscosity; LIF Doppler spectroscopy; plasma hole; viscous vortex; 粘性渦; プラズマ; 流れ場; ドップラーシフト; 誘起蛍光法

We have observed a vortex with a density cavity in its core, in a magnetized cylindrical plasma. The density of the hole region is one tenth of that in the peripheral plasma. The space potential has a strong peak in the core, and the resulting radial electric field becomes as high as 40 V/cm, which drives an azimuthal rotation at a supersonic velocity. It is also found that in the core region, centrifugal force dominates the electric force to be balanced with the Lorenz force, leading to a rigid rotation of the core. The flow velocity field has benn measured with a directional Langmuir probe, and it revealed that the plasma hole has a sink flow to the core on a plane perpendicular to the magnetic field and also an axial flow. The vorticity distribution determined by the flow velocity field shows localization near the center axis, which means that the viscosity of the plasma is finite and causes radial transport of vorticity. According to the flow velocity field and the vorticity distribution, the plasma hole is identified as a Burgers vortex, which is intrinsic in viscous fluids and is observed in a plasma for the first time. The effective viscosity estimated from the characteristic scale length of vorticity localization exhibits an anomaly, which is three orders of magnitude higher than the classical value.

在磁化圆柱形等离子体中，我们观察到一个中心有密度空腔的涡旋。空穴区的密度是外围等离子体的十分之一。空间电势在核中具有强峰值，并且由此产生的径向电场变得高达40 V/cm，其驱动以超音速的方位角旋转。在核区，离心力占主导地位的电力与洛伦兹力平衡，导致核的刚性旋转。用定向朗缪尔探针测量了流场，发现等离子体孔在垂直于磁场的平面上有向芯的下沉流，也有轴向流。由流速场确定的涡量分布在中心轴附近表现出局部化，这意味着等离子体的粘性是有限的，并导致涡量的径向输运。根据流场和涡量分布，将等离子体空洞确定为Burgers涡，这是粘性流体中的一种本征涡，也是首次在等离子体中观测到。由涡度局部化特征尺度长度估算的有效粘滞系数出现异常，比经典值高出三个数量级。

项目成果

Tripolar Vortex in a Plasma

等离子体中的三极涡旋

• 发表时间: 2005
• 期刊: IEEE Transactions on Plasma Science Vol.33 No.2
• 作者: Jan Bergstrom;Yutaro Suzuki;鈴木雄太郎・三村晃一;岩槻邦男;鈴木雄太郎(分担執筆);A.Okamoto;A.Okamoto;A.Okamoto;A.Okamoto
• 通讯作者: A.Okamoto

Plasma Flow Shear and Formation of Viscous Vortex

等离子体流剪切和粘性涡旋的形成

• 发表时间: 2004
• 期刊: Journal of Plasma and Fusion Researches 80
• 作者: 田中雅慶 他;M.Y.Tanaka et al.;M.Y.Tanaka et al.;A.Okamoto et al.;M.Y.Tanaka;A.Okamoto et al.;A.Okamoto et al.;M.Y.Tanaka;A.Okamoto et al.;M.Y.Tanaka et al.;J.Vranges et al.;田中雅慶;M.Y.Tanaka
• 通讯作者: M.Y.Tanaka

M.Y.Tanaka et al.: "Formation of Visco-dissipative Vortex and Quasi-neutrality Breaking in a Magnetoplasma"Physica Scripta. (印刷中). (2004)

M.Y.Tanaka 等人：“磁等离子体中粘性耗散涡流的形成和准中性破裂”Physica Scripta（出版中）。

Formation of Visco-dissipative Vortex and Quasi-neutrality Breaking in a Magnetoplasm

磁质中粘性耗散涡旋的形成和准中性破缺

• 发表时间: 2004
• 期刊: Physica Scripta T107
• 作者: 田中雅慶 他;M.Y.Tanaka et al.;M.Y.Tanaka et al.;A.Okamoto et al.;M.Y.Tanaka;A.Okamoto et al.;A.Okamoto et al.;M.Y.Tanaka;A.Okamoto et al.;M.Y.Tanaka et al.
• 通讯作者: M.Y.Tanaka et al.

田中雅慶: "プラズマフロー速度シアと粘性渦形成"プラズマ・核融合学会誌. Vol.80・4(印刷中). (2004)

Masayoshi Tanaka：“等离子体流速剪切和粘性涡流形成”，日本等离子体与核聚变学会杂志，第 80 卷，4（出版中）。