The magnetic field generated in an initially unmagnetized and anisotropic inhomogeneous plasma by the development of the Weibel instability is strongly nonuniform. For the case of a plasma where the anisotropy arises from two (relativistic) counterstreaming electron beams it is shown, both analytically and numerically, that this instability develops a spatial ''resonant''-type singularity. The largest magnetic field is generated around this singularity and has opposite polarities. In the case of one-dimensional (1D) perturbations, a current layer is formed very rapidly at the resonance position, almost independently of the characteristic scale of the initial perturbation. In 2D, numerical simulations show that a chain of current vortices is formed.
|Autori interni:||CALIFANO, FRANCESCO|
|Autori:||Califano F; Pegoraro F; Bulanov SV|
|Titolo:||Spatial structure and time evolution of the Weibel instability in collisionless inhomogeneous plasmas|
|Anno del prodotto:||1997|
|Digital Object Identifier (DOI):||10.1103/PhysRevE.56.963|
|Appare nelle tipologie:||1.1 Articolo in rivista|