Nonlinear self-focusing in strongly magnetized pair plasma
Nonlinear self-focusing in strongly magnetized pair plasma
复制标题
强磁化对等离子体中的非线性自聚焦
DOI：
10.1103/physreve.102.013211
复制
发表时间：
2020
影响因子：
2.4
通讯作者：
Lyutikov, Maxim
中科院分区：
文献类型：
--
作者：
Lyutikov, Maxim
强辐射场可以改变等离子体的性质和相应的折射率，并导致诸如自聚焦等非线性传播效应。我们估计了对等离子体中圆极化波的相应效应，在非磁化和强磁主导的情况下都是如此。首先，在未磁化的对等离子体中，有质动力不会导致电荷分离，而是导致密度耗尽。其次，对于与天体物理相关的脉冲星磁层等离子体[和可能的快射电暴(FRB)轨迹]，其中回旋频率支配等离子体频率和电磁波的频率，我们证明：(I)由于波场中有效质量的变化，几乎不存在非线性；(Ii)有质动力是，如果与未磁化的情况相比(是外部磁场和波的电场)，它会减少一个因子；对于沿密度等离子体对中的恒定磁场传播的辐射束，有质动力导致环形电流的出现，从而导致束内磁场减小一个系数。讨论了FRB在物理上的应用，得出结论：对于FRB的参数，主导磁场完全抑制了非线性自聚焦或丝化。
An intense radiation field can modify plasma properties and the corresponding refractive index and lead to nonlinear propagation effects such as self-focusing. We estimate the corresponding effects in pair plasmas for circularly polarized waves, in both unmagnetized and strongly magnetically dominated cases. First, in the unmagnetized pair plasma the ponderomotive force does not lead to charge separation but to density depletion. Second, for astrophysically relevant plasmas of pulsar magnetospheres [and possible loci of fast radio bursts (FRBs)], where the cyclotron frequencydominates over the plasma frequencyand the frequency of the electromagnetic wave, we show that (i) there is virtually no nonlinearity due to changing effective mass in the field of the wave; (ii) the ponderomotive force is, which is reduced by a factorif compared to the unmagnetized case (is the external magnetic field andis the electric field of the wave); and (iii) for a radiation beam propagating along a constant magnetic field in the pair plasma with density, the ponderomotive force leads to the appearance of circular currents that lead to a decrease of the field within the beam by a factor. Applications to the physics of FRBs are discussed; we conclude that for the parameters of FRBs, the dominant magnetic field completely suppresses nonlinear self-focusing or filamentation.