Intermittent transport in the plasma periphery of the T-10 tokamak
Intermittent transport in the plasma periphery of the T-10 tokamak
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T-10 托卡马克等离子体外围的间歇传输
DOI：
10.1088/0741-3335/46/4/004
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发表时间：
2004
影响因子：
2.2
通讯作者：
L. Khimchenko
中科院分区：
文献类型：
--
作者：
G. Kirnev;V. Budaev;S. Grashin;E. V. Gerasimov;L. Khimchenko
在T-10托卡马克装置上进行的等离子体外围研究表明，随着等离子体平均密度的增加，刮除层（SOL）中垂直反常粒子通量显著增加。径向传输的加强被发现发生在平均电子密度高于阈值水平，这取决于一个等离子体电流Ip。阈值水平的值约为格林沃尔德密度的0.3倍。朗缪尔探针测量的SOL等离子体参数表明，间歇事件可以发挥重要作用的跨场传输。等离子体参数的间歇性行为与具有高密度的等离子体区域（或结构）的形成和传播相关联。这些构造沿径向和极向运动。径向运动主要指向SOL中的真空容器壁。高密度等离子体结构的径向速度从最后一个封闭通量表面附近的1000 m s-1降低到真空室壁处的200 m s-1。结构的径向尺寸也随着小半径从3到0.5 cm而减小。极向速度等于1000-1300 m s-1，并且指向离子反磁速度;等离子体结构的极向尺寸为2-3 cm。所观察到的等离子体结构可以负责超过50%的总径向湍流粒子通量。T-10的结果支持的假设，间歇性对流，而不是扩散可以定义的跨场传输。
Plasma periphery investigation performed in the T-10 tokamak has shown an essential increase of the perpendicular anomalous particle flux in the scrape-off layer (SOL) with an average plasma density rise. The strengthening of the radial transport is found to occur at an average electron density above a threshold level, which depends on a plasma current Ip. The value of the threshold level is about 0.3 times the Greenwald density. Langmuir probe measurements of SOL plasma parameters indicate that intermittent events can play a significant role in the cross-field transport. Intermittent behaviour of the plasma parameters is associated with formation and propagation of the plasma regions (or structures) with high density. The structures move in radial and poloidal directions. Radial movement is predominantly directed to the vacuum vessel wall in the SOL. The radial velocity of the high density plasma structures reduces from 1000 m s−1 near the last closed flux surface to 200 m s−1 at the wall of the vacuum chamber. The radial size of the structures also decreases with minor radius from 3 to 0.5 cm. The poloidal velocity is equal to 1000–1300 m s−1 and is directed towards an ion diamagnetic velocity; the poloidal size of the plasma structures is 2–3 cm. The observed plasma structures can be responsible for more than 50% of the total radial turbulent particle flux. T-10 results support the hypothesis that intermittent convection rather than diffusion can define the cross-field transport.