论文标题
MHD模拟现场反向配置的磁压缩
MHD Simulations on Magnetic Compression of Field Reversed Configurations
论文作者
论文摘要
长期以来，人们一直提出了磁压缩的一种有前途的方法，用于在磁场逆转配置（FRC）中加热的有前途的方法，但是，由于其高度动态的性质超出了一维（1d）绝热理论模型[R. R. R. L. Spencer等人，物理。流体26，1564（1983）]。在这项工作中，使用Nimrod代码[C. C. R. Sovinec等，J。Comput。物理。 195，355（2004）]及其与1D理论的比较。已经探索了该理论假设对压缩过程的影响，并研究了压缩过程中FRC的详细概况。压力演化与各种初始条件下的理论预测一致。 The axial contraction of the FRC can be affected by the initial density profile and the ramping rate of the compression magnetic field, but the theoretical predictions on the FRC's length in general and the relation $r_s=\sqrt{2}r_o$ in particular hold approximately well during the whole compression process, where $r_s$ is the major radius of FRC separatrix and $r_o$ is that of the magnetic axis.密度和温度的演变可能会受到初始平衡曲线和压缩磁场的渐变速率的显着影响。在压缩过程中，FRC的主要半径是另一个参数，它易受压缩场的坡道速率。基本上，对于相同的磁压缩比，峰密度更高，而FRC的半径$ r_s $小于理论预测。
The magnetic compression has long been proposed a promising method for the plasma heating in a field reversed configuration (FRC), however, it remains a challenge to fully understand the physical mechanisms underlying the compression process, due to its highly dynamic nature beyond the one-dimensional (1D) adiabatic theory model [R. L. Spencer et al., Phys. Fluids 26, 1564 (1983)]. In this work, magnetohydrodynamics (MHD) simulations on the magnetic compression of FRCs using the NIMROD code [C. R. Sovinec et al., J. Comput. Phys. 195, 355 (2004)] and their comparisons with the 1D theory have been performed. The effects of the assumptions of the theory on the compression process have been explored, and the detailed profiles of the FRC during compression have been investigated. The pressure evolution agrees with the theoretical prediction under various initial conditions. The axial contraction of the FRC can be affected by the initial density profile and the ramping rate of the compression magnetic field, but the theoretical predictions on the FRC's length in general and the relation $r_s=\sqrt{2}r_o$ in particular hold approximately well during the whole compression process, where $r_s$ is the major radius of FRC separatrix and $r_o$ is that of the magnetic axis. The evolutions of the density and temperature can be affected significantly by the initial equilibrium profile and the ramping rate of the compression magnetic field. During the compression, the major radius of the FRC is another parameter that is susceptible to the ramping rate of the compression field. Basically, for the same magnetic compression ratio, the peak density is higher and the FRC's radius $r_s$ is smaller than the theoretical predictions.
