Electron Weibel instability and quasi-magnetostatic structures in an expanding collisionless plasma

• Published in: Reviews of modern plasma physics 2024-04, Vol.8 (1), Article 17
• Main Authors: Kocharovsky, Vladimir V., Nechaev, Anton A., Garasev, Mikhail A.
• Format: Article
• Language: English
• Subjects: Astronomy; Astrophysics and Cosmology; Lasers; Nuclear Fusion; Optical Devices; Optics; Photonics; Physics; Physics and Astronomy; Plasma Physics; Special Topics
• ISSN: 2367-3192; 2367-3192
• DOI: 10.1007/s41614-024-00157-4

We outline transient quasi-magnetostatic phenomena associated with Weibel-type instabilities, mainly the formation and decay of the current filaments and sheets. We consider a collisionless expansion of an anisotropic plasma cloud with hot electrons into a background plasma and take into account an external magnetic field in different geometries entailing (i) a hot-electron spot of a circular or cylindrical form within an initial-value problem or a finite-time injection of electrons from a target surface, (ii) an external magnetic field with three orthogonal orientations: perpendicular to the target or along it, directed either across or parallel to a long axis of the hot-electron spot, and (iii) inhomogeneous layers of cold background plasma of different spatial scales and densities. We heed typical laser-plasma experiments. We outline development of the principal structures of current linked with distinct forms of the anisotropic electron velocity distribution using particle-in-cell modeling of the instability process for diverse sets of the attributes (i)–(iii). Applications to the analysis of laboratory and space plasma problems involving an explosive development of the small-scale self-consistent magnetic turbulence due to filamentation of the electric current are discussed.