相关论文: Sheath constraints on turbulent magnetised plasmas
The Debye sheath is known to vanish completely in magnetised plasmas for a sufficiently small electron gyroradius and small angle between the magnetic field and the wall. This angle depends on the current onto the wall. When the Debye…
We consider a magnetised plasma in contact with an absorbing planar wall, where the angle $\alpha$ between the magnetic field and the wall is small, $\alpha \ll 1$ (in radians) and the system is symmetric tangential to the wall. The finite…
Between a plasma and a solid target lies a positively charged sheath of several Debye lengths $\lambda_{\rm D}$ in width, typically much smaller than the characteristic length scale $L$ of the main plasma. This scale separation implies that…
Most plasmas have a very thin sheath compared with the plasma dimension. This necessitates separate calculations of the plasma and sheath. The Bohm criterion provides the boundary condition for calculation of plasma profiles. To calculate…
Biased electrodes are common components of plasma sources and diagnostics. The plasma-electrode interaction is mediated by an intervening sheath structure that influences properties of the electrons and ions contacting the electrode…
The electron sheath is a particular electron-rich sheath with negative net charges where plasma potential is lower than the biased electrode. Here an improved understanding of electron sheath theory is provided using both fluid and kinetic…
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,…
The sheath formation in a weakly magnetized collisionless electronegative plasma consisting of electrons, negative and positive ions has been numerically investigated using the hydrodynamic equations. The electrons and negative ions are…
The potential difference between a floating emitting surface and the plasma surrounding it has been described by several sheath models, including the space-charge-limited sheath, the electron sheath with high emission current, and the…
Charged particles gyrate around magnetic field lines, a property that is exploited to confine plasma in magnetic confinement fusion devices. Typically, the gyroradius is small compared to the system size and thus the gyromotion can be…
Three-dimensional (3D) etching of materials by plasmas is an ultimate challenge in microstructuring applications. A method is proposed to reach a controllable 3D structure by using masks in front of the surface in a plasma etch reactor in…
The magnetic presheath is a boundary layer occurring when magnetized plasma is in contact with a wall and the angle $\alpha$ between the wall and the magnetic field $\vec{B}$ is oblique. Here, we consider the fusion-relevant case of a…
A theory for presheath-like structures near probes biased at and above the plasma potential is developed for collisionless plasmas with an electron-neutral mean free path on the order of the chamber scale. The theory predicts presheath-like…
Experimental data compiled over five decades of dense plasma focus research is consistent with the snowplow model of sheath propagation, based on the hypothetical balance between magnetic pressure driving the plasma into neutral gas ahead…
Sheath formation near biased electrodes in magnetic fields parallel to the wall is an understudied topic, especially within the context of Z-pinch fusion experiments. We perform 1X-2V Boltzmann-Poisson simulations of an axial cut at the…
The plasma exit flow speed at the sheath entrance is constrained by the Bohm criterion. The so-called Bohm speed regulates the plasma particle and power exhaust fluxes to the wall, and it is commonly deployed as a boundary condition to…
In this paper, the central concern is to analyze the influence of the forces that controls the ion dynamics inside a magnetized plasma sheath under collisionless conditions. The ionization effects are considered within the sheath. The…
When an unmagnetized plasma comes in contact with a material surface, the difference in mobility between the electrons and the ions creates a nonneutral layer known as the Debye sheath (DS). However, in magnetic fusion devices, the open…
When a plasma sheath forms next to a dielectric wall, material properties determine electron absorption and reflection from the surface, impacting the sheath formation and structure. The low energy regime of this interaction is often not…
Bounded plasmas are characterized by a rapid but smooth transition from quasi-neutrality in the volume to electron depletion close to the electrodes and chamber walls. The thin non-neutral region, the boundary sheath, comprises only a small…