Terasaka K, Yoshimura S, Ogiwara K, Aramaki M, Tanaka M Y
Phys Plasmas. 2010 Jul;17(7). doi: 10.1063/1.3457139. Epub 2010 Jul 27.
The flow structure of ions in a diverging magnetic field has been experimentally studied in an electron cyclotron resonance plasma. The flow velocity field of ions has been measured with directional Langmuir probes calibrated with the laser induced fluorescence spectroscopy. For low ion-temperature plasmas, it is concluded that the ion acceleration due to the axial electric field is important compared with that of gas dynamic effect. It has also been found that the detachment of ion stream line from the magnetic field line takes place when the parameter |f(ci)L(B)∕V(i)| becomes order unity, where f(ci), L(B), and V(i) are the ion cyclotron frequency, the characteristic scale length of magnetic field inhomogeneity, and the ion flow velocity, respectively. In the detachment region, a radial electric field is generated in the plasma and the ions move straight with the E×B rotation driven by the radial electric field.
在电子回旋共振等离子体中对发散磁场中离子的流场结构进行了实验研究。利用激光诱导荧光光谱校准的定向朗缪尔探针测量了离子的流速场。对于低离子温度等离子体，得出的结论是，与气体动力学效应相比，轴向电场引起的离子加速很重要。还发现，当参数|f(ci)L(B)∕V(i)|变为单位量级时，离子流线会从磁力线分离，其中f(ci)、L(B)和V(i)分别是离子回旋频率、磁场不均匀性的特征尺度长度和离子流速。在分离区域，等离子体中会产生径向电场，离子在径向电场驱动的E×B旋转作用下直线运动。
