Long pulse FRC sustainment with enhanced edge driven rotating magnetic field current drive
Long pulse FRC sustainment with enhanced edge driven rotating magnetic field current drive
复制标题
具有增强边缘驱动旋转磁场电流驱动的长脉冲 FRC 维持
DOI：
10.1088/0029-5515/45/3/003
复制
发表时间：
2005
期刊：
影响因子：
3.3
通讯作者：
R. Milroy
中科院分区：
文献类型：
--
作者：
A. Hoffman;H.Y. Guo;K. Miller;R. Milroy
在平移、约束和维持实验中，通过旋转磁场（RMFs）形成并维持了高达50个正常通量衰减时间的场反转构型（FRCs）。对于这些较长的脉冲时间，已经观察到一个新的现象：切换到更高的性能模式，通过更浅的RMF穿透，更高的产生极向与RMF驱动场的比率，以及更低的总体等离子体电阻率。这种模式切换总是伴随着一个自发发展的环形场，其幅度高达峰值极向场的20%，并可能由其触发。全球数据不能用先前基于均匀电子旋转速度的RMF理论或基于均匀等离子体电阻率的数值计算来解释，但在许多方面与使用强烈变化的电阻率剖面进行的新计算一致。为了更真实地模拟具有这种非均匀电阻率分布的RMF驱动FRCs，建立了一个内外电子旋转速度和电阻率分开的双刚性转子模型。该模型的结果表明，RMF驱动在窄边缘层中导致非常高的电阻率，并且更高性能模式的特征是在FRC的大部分上电阻率急剧降低。
Field reversed configurations (FRCs) have been formed and sustained for up to 50 normal flux decay times by rotating magnetic fields (RMFs) in the translation, confinement, and sustainment experiment. For these longer pulse times a new phenomenon has been observed: switching to a higher performance mode delineated by shallower RMF penetration, higher ratios of generated poloidal to RMF drive field, and lower overall plasma resistivity. This mode switching is always accompanied by, and perhaps triggered by, the spontaneous development of a toroidal field with a magnitude up to 20% of the peak poloidal field. The global data cannot be explained by previous RMF theory based on uniform electron rotational velocities or by numerical calculations based on uniform plasma resistivity, but agrees in many respects with new calculations made using strongly varying resistivity profiles. In order to more realistically model RMF driven FRCs with such non-uniform resistivity profiles, a double rigid rotor model has been developed with separate inner and outer electron rotational velocities and resistivities. The results of this modelling suggest that the RMF drive results in very high resistivity in a narrow edge layer, and that the higher performance mode is characterized by a sharp reduction in resistivity over the bulk of the FRC.