Eliasson B, Shukla P K
Institut für Theoretische Physik IV, Fakultät für Physik und Astronomie, Ruhr-Universität Bochum, D-44780 Bochum, Germany.
Phys Rev Lett. 2007 Nov 16;99(20):205005. doi: 10.1103/PhysRevLett.99.205005. Epub 2007 Nov 15.
Recent laboratory experiments [Stenzel et al., Phys. Rev. Lett. 96, 095004 (2006)10.1103/PhysRevLett.96.095004] have demonstrated interesting phenomena of propagating nonlinear whistler structures (spheromaks) and stationary field-reversed configurations, whose magnetic fields exceed the ambient magnetic field strength. Our objective here is to present simulation studies for these nonlinear whistler structures based on the three-dimensional nonlinear electron magnetohydrodynamic equations. The robustness and longevity of the propagating whistler spheromaks found in the experiments are confirmed numerically. Varying the toroidal field of the spheromak in the initial conditions, we find that the polarity and the amplitude of the toroidal field determine the propagation direction and speed of the spheromak. Our simulation results are in excellent agreement with those observed in the laboratory experiments.
近期的实验室实验[施滕泽尔等人，《物理评论快报》96, 095004 (2006)10.1103/PhysRevLett.96.095004]已经证明了传播的非线性啸叫结构（球形马克）和稳态场反转构型的有趣现象，其磁场强度超过了周围磁场强度。我们这里的目标是基于三维非线性电子磁流体动力学方程对这些非线性啸叫结构进行模拟研究。实验中发现的传播啸叫球形马克的稳健性和持久性通过数值计算得到了证实。在初始条件下改变球形马克的环形场，我们发现环形场的极性和幅度决定了球形马克的传播方向和速度。我们的模拟结果与实验室实验中观察到的结果非常吻合。
