Electric field in spatially inhomogeneous non-neutral plasma

Evolution of electron cross-field transport induced by an equilibrium azimuthal electric field in an $\mathrm{E}\times\mathrm{B}$ Hall thruster discharge under an azimuthally inhomogeneous neutral supply

The electron cross-field transport by the induced azimuthal electric field in a Hall thruster exhibits the mobility scaled by $1/B$. This study investigates parameters affecting this transport over a Hall thruster's distinct regions, such as the ionization, acceleration, and plume region. The main focus is on the nonzero equilibrium azimuthal electric field induced by an azimuthally inhomogeneous neutral supply. A fast Fourier transform analysis of the plasma structure reveals that the wavenumber $k$ of the azimuthal plasma structure increases from $k=2$, which is the input condition, to $k=4$…

空间非均匀系统中可压缩流体的慢无粘流动

Slow inviscid flows of a compressible fluid in spatially inhomogeneous systems

考虑一种理想的可压缩流体，由于存在一些静态外力，平衡密度是给定的坐标函数。利用哈密顿形式研究了不扰动密度的慢流问题。对于任意给定的涡度场拓扑，导出了系统的运动方程。建立了冻结涡线拉格朗日量的一般形式。本文研究了几种非均匀物理模型中细长涡丝运动的局域诱导近似。

协变本构关系、Landau阻尼与非平稳非均匀等离子体

Covariant Constitutive Relations, Landau Damping and Non-stationary Inhomogeneous Plasmas

协变线性电磁本构关系模型的制定，具有广泛的适用性的色散和非均匀介质的磁化率张量的计算。一个微扰框架是用来推导出一个线性本构关系的全球中性等离子体，使之能够在这方面描述一个广义的朗道阻尼机制的非平稳非均匀等离子体状态。

Effect of collisions on the plasma sheath in the presence of an inhomogeneous magnetic field

A low-pressure magnetized plasma is studied to find the dependency of sheath properties on ion-neutral collisions in presence of an inhomogeneous magnetic field. A self-consistent one-dimensional two-fluid hydrodynamic model is considered, and the system of equations is solved numerically. The study reveals that the width of the plasma sheath expands and space charge increases with collisions. The ion-neutral collisions and the inhomogeneous magnetic field restrict the ions to move towards the surface. The movement of the ions towards the wall can be controlled by choosing a suitable configura…

Spatially inhomogeneous acceleration of electrons in solar flares

The imaging spectroscopy capabilities of the Reuven Ramaty high energy solar spectroscopic imager (RHESSI) enable the examination of the accelerated electron distribution throughout a solar flare region. In particular, it has been revealed that the energisation of these particles takes place over a region of finite size, sometimes resolved by RHESSI observations. In this paper, we present, for the first time, a spatially distributed acceleration model and investigate the role of inhomogeneous acceleration on the observed X-ray emission properties. We have modelled transport explicitly examinin…

Magnetic field generation by an inhomogeneous return current

A new generation mechanism of the magnetic field in an inhomogeneous collisionless plasma with a beam component is proposed. We show that even though the current and charge neutralities are initially satisfied, the current neutrality is eventually violated if there is an inhomogeneity, so that the magnetic field is generated. By conducting ab initio two-dimensional particle-in-cell simulations, we demonstrate that the magnetic field is generated as expected. The new generation mechanism of the magnetic field can play an important role in the current universe because cosmic rays can be regarded…