<p><span>We propose a</span>n analytical model <span>f</span>or a distributed current sheet separating two regions of anisotropic collisionless plasma with different values of <span>magnetization</span> and different effective temperatures of the energy distributions of electrons and ions <span>[1, 2]</span>. <span>Namely, we find a solution to the Vlasov&#8211;Maxwell equations in the form of </span>a superposition of arbitrary isotropic <span>distribution functions</span> of particle <span>energy</span>, <span>each </span>multiplied by a Heaviside step function <span>of</span> one of the projections of the generalized momentum. This solution admits the shear of magnetic <span>field</span> lines and the presence of several ion components with different effective temperatures and localized countercurrents <span>with arbitrary densities and spatial shifts</span>.</p><p>It is shown that <span>a</span> <span>certain</span> <span>choice </span>of the energy distribution of particles (Maxwellian, kappa, and others) <span>determine only the </span>quantitative, not qualitative, properties of the constructed models. <span>Sheets</span> containing several fractions of particles with countercurrents, shifted relative to each other in space and having different scales, allow multiple non-monotonic changes in the magnetic field value and direction. The total <span>thickness of the current </span><span>sheet</span> is determined by the values <span>o</span>f <span>s</span>hifts between <span>the </span>currents of <span>the </span><span>plasma</span> fractions with the highest energy content and <span>by </span>the typical gyroradii of the<span>ir</span> particles.</p><p><span>We carried out p</span><span>article-in-cell </span><span>simulati</span>ons of <span>the </span>analytically constructed magnetic transition layers in one-dimensional and two-dimensional geometries. The stability of the simplest models of the considered class is demonstrated, which is consistent with qualitative estimates of stability against Weibel-type perturbations.</p><p>The proposed models make it possible to interpret<span> modern </span>data of satellite observations of multicomponent current sheets in the regions of <span>the </span>magnetopause <span>and </span>the bow shock, solar wind magnetic clouds and high coronal magnetic structures, and to analyze the<span>ir</span> fine structure taking into account the observed suprathermal, nonequilibrium particle fractions.</p><p>The investigation of stability of current sheets was supported by the Russian Science Foundation under grant No. 20-12-00268.</p><p><span>1. K</span><span>ocharovsky V. V., Kocharovsky Vl. V., Martyanov V. Yu., Nechaev A. A. An analytical model for the current structure of the magnetosheath boundary in a collisionless plasma // Astron. Lett. 2019. V. 45, No. 8. P. 551&#8211;564. doi:10.1134/S1063773719080048 .</span></p><p><span>2. </span><span>Kocharovsky V. V., Kocharovsky Vl. V., Nechaev A. A.</span> <span>Analytical model of a magnetopause in a multicomponent collisionless plasma with a kappa energy distribution of particles </span><span>// </span><span>Doklady Physics</span><span>. 2021. </span><span>V</span><span>. 496. </span><span>In press.</span></p>
Force balance in current sheets in collisionless plasma
