On the formation of three types of e.m. elements in a current-carrying plasma with double flows

Abstract We explain in terms of Vlasov kinetic approach under the conditions of hot collisionless plasmas the nature of three topologically different and orthogonal magnetic elements in a space plasma: current sheets, magnetic ropes, and magnetic islands. These elements appear in the original current-carrying plasmas (CCP) with double flows. The elements are basic for constructing a 3D structure of the heliospheric sheet and magnetotails. Original double flows and currents in the CCP are in a diamagnetic state and are mutually perpendicular. The elements structuring the CCP i.e., current sheets, magnetic ropes, magnetic islands appear as the result of the electromagnetic (e.m.) Weibel type instability on three orthogonal directions of the wave vector for perturbations. Current sheet elements form due to a plane pinch effect of the original current with the wave vector directed perpendicular both to original current and double flow. Magnetic rope structures are e.m. perturbations excited by original double flows in plane sheet with the wave vector along current. Magnetic island structures are associated with tearing mode e.m. perturbations with the wave vector along the flow. The governing parameter for the excitation of different elements is a parameter of plasma anisotropy. Its value and sign depends on parameters of the original CCP with double flows and depends also on the polarization of the mode e.m. field for a given direction of the wave vector. This parameter allows a diagnostic of scale and type of structures excited in a plasma. When the anisotropy parameter is positive, we get a magnetic Debye scale defining the scale of the excited magnetic elements. When it is negative, we have no excitation of the given magnetic elements.