Origins of spatial modulation of stationary electron and ion currents to the wall in discharge plasma with/without magnetic field at low gas pressure are studied in the experiments and 2D PIC MCC simulations. It is shown that a non-uniformity of ion and electron fluxes to the wall is induced by (a) a non-planar topology on the emissive wall, (b) a difference in the secondary electron emission yields of materials in segmented wall or (c) an inclination of the external magnetic field. The transition in the sheath structure over the grooved emissive surface from a developed sheath to a collapsed one caused by the increase of electron energy enlarges the alteration of the ion and electron currents over the grooved or segmented surfaces. The experimental study of the plasma-emissive wall sheath transition was carried out with hexagonal boron nitride wall samples grooved with the characteristic size of 1 mm and 5 mm, which is about of the Debye length. In kinetic simulations, this phenomenon is analyzed in terms of the electron and ion energy distribution functions. An external oblique magnetic field applyed to the dc discharge is found to redistribute the plasma and the periodical structure with the spikes of electron and ion densities forms This phenomena causes the non-uniform spatial distribution of electron and ion currents to the wall. The spikes in electron and ion densities became more pronounced with an increase of magnetic field incidence angle.

在实验和 2D PIC MCC 模拟中研究了在低气压下有/没有磁场的放电等离子体中静止电子和离子电流对壁的空间调制的起源。结果表明，由于（a）发射壁上的非平面拓扑结构，（b）分段壁中材料的二次电子发射产率差异或（ c) 外部磁场的倾斜。由于电子能量的增加，凹槽发射表面上的鞘结构从展开的鞘到塌陷的鞘的转变扩大了带凹槽或分段表面上的离子和电子电流的改变。等离子体发射壁鞘转变的实验研究是用六方氮化硼壁样品进行的，其特征尺寸为1毫米和5毫米，约为德拜长度。在动力学模拟中，根据电子和离子能量分布函数来分析这种现象。发现应用于直流放电的外部倾斜磁场重新分布等离子体和周期性结构，电子和离子密度形成尖峰。这种现象导致电子和离子电流在壁上的空间分布不均匀。随着磁场入射角的增加，电子和离子密度的尖峰变得更加明显。这种现象是根据电子和离子能量分布函数来分析的。发现应用于直流放电的外部倾斜磁场重新分布等离子体和周期性结构，电子和离子密度形成尖峰。这种现象导致电子和离子电流在壁上的空间分布不均匀。随着磁场入射角的增加，电子和离子密度的尖峰变得更加明显。这种现象是根据电子和离子能量分布函数来分析的。发现应用于直流放电的外部倾斜磁场重新分布等离子体和周期性结构，电子和离子密度形成尖峰。这种现象导致电子和离子电流在壁上的空间分布不均匀。随着磁场入射角的增加，电子和离子密度的尖峰变得更加明显。