Kawamori Eiichirou, Ono Yasushi
High Temperature Plasma Center, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656, Japan.
Phys Rev Lett. 2005 Aug 19;95(8):085003. doi: 10.1103/PhysRevLett.95.085003. Epub 2005 Aug 18.
The effect of ion skin depth on the relaxation of merging spheromaks to a field-reversed configuration (FRC) is studied experimentally for a wide range of size parameter S* (ratio of minor radius to ion skin depth) from 1 to 7. The two merging spheromaks are observed to relax to an FRC or a new spheromak depending on whether the initial poloidal eigenvalue is smaller or larger than a threshold value. The bifurcation value is found to increase with decreasing size parameter S*, indicating that the low-S* condition provides a wide bifurcated range of relaxation to an FRC. The FRC-style relaxation under the low-S* conditions was accompanied by the suppression of the low-n modes (n is the toroidal mode number) activity. The fast rotations of the modes were followed by suppression of the low-n modes.
在大小参数S*（小半径与离子趋肤深度之比）从1到7的广泛范围内，通过实验研究了离子趋肤深度对合并球形马克向场反向配置（FRC）弛豫的影响。观察到两个合并的球形马克会弛豫到FRC或一个新的球形马克，这取决于初始极向本征值是小于还是大于一个阈值。发现分岔值随着大小参数S的减小而增加，这表明低S条件为弛豫到FRC提供了一个宽的分岔范围。在低S*条件下的FRC式弛豫伴随着低n模（n为环向模数）活动的抑制。模式的快速旋转之后是低n模的抑制。
