中文摘要：

采用三维模型,使用混合网格质点法对等离子体入射偶极子磁场产生的磁场膨胀进行数值模拟.在模拟中考虑了高能等离子体注入两种不同类型磁场的情况：等离子体注入没有背景磁场的偶极子磁场和等离子体注入有背景磁场的偶极子磁场.研究表明背景磁场的存在不仅改变了粒子的分布,还改变了磁场膨胀的程度.还研究了注入的高能等离子体的速度对磁场膨胀的影响,结果表明入射的高能等离子体速度越大,磁场膨胀的程度就越大.对于低的入射速度,入射粒子在偶极子磁场中的回旋半径与偶极子磁场的特征长度相比较小,粒子被磁场束缚,对偶极子磁场的影响可以忽略.

英文摘要：

Using three-dimentional model, the hybrid particle in cell method is used to simulate the inflation of magnetic field by injecting plasma into dipole magnetic field. Two different types of magnetic field expansions are considered, the high density plasma is injected into a dipole magnetic field with or without a background magnetic field. It is found that the existence of background magnetic field not only changes the particle distribution, but also significantly changes the extent of magnetic field inflation. The effects of plasma injection velocity on the magnetic field inflation are also studied. It is shown that the higher the injection velocity, the larger is the size of the inflated magnetic bubble. For the lower injection velocity, the gyroradius of the injected particle is small compared with the dipole field scale length, so that the particles are trapped in the dipole field and the effect on dipole magnetic field can be ignored.