Numerical simulation of current-free double layers created in a helicon plasma device

2012 ◽  
Vol 19 (9) ◽  
pp. 093507 ◽  
Author(s):  
Sathyanarayan Rao ◽  
Nagendra Singh
Keyword(s):  
Numerical Simulation ◽  
Double Layers ◽  
Helicon Plasma ◽  
Plasma Device

scholarly journals Formation mechanisms of laboratory double layers in triple plasma devices

1987 ◽  
Vol 5 (2) ◽  
pp. 219-231 ◽  
Author(s):  
Chung Chan
Keyword(s):  
Laboratory Experiments ◽  
Virtual Cathode ◽  
Ion Trapping ◽  
Double Layers ◽  
Formation Mechanisms ◽  
Triggering Mechanism ◽  
Potential Wells ◽  
Trapped Ion ◽  
Plasma Device ◽  
Type Potential

The evolution processes of double-layers have been studied in a series of laboratory experiments using a triple plasma device. It was found that the existence of virtual cathode type potential wells at the electron injection boundary was the dominant triggering mechanism. The rapid growth of the potential well led to collisionless ion trapping and the establishment of the necessary trapped ion population. For double layers with small potential drops, collisionless ion trapping actually induced ion–ion streaming instabilities and the formation of ion phase-space vortices. In this regime, the system often exhibited relaxation type oscillations which corresponded to the disruption and the recovery of the double layers.

Numerical Simulation on the Electrophoretic Motion of Multiple Particles in Microchannels

2004 ◽  
Author(s):  
Chunzhen Ye ◽  
Dongqing Li
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Electric Field ◽  
Particle Motion ◽  
Outer Region ◽  
Numerical Results ◽  
The Other ◽  
Double Layers ◽  
Rectangular Microchannel ◽  
Moving Particle

This paper considers the electrophoretic motion of multiple spheres in an aqueous electrolyte solution in a straight rectangular microchannel, where the size of the channel is close to that of the particles. This is a complicated 3-D transient process where the electric field, the flow field and the particle motion are coupled together. The objective is to numerically investigate how one particle influences the electric field and the flow field surrounding the other particle and the particle moving velocity. It is also aimed to investigate and demonstrate that the effects of particle size and electrokinetic properties on particle moving velocity. Under the assumption of thin electrical double layers, the electroosmotic flow velocity is used to describe the flow in the inner region. The model governing the electric field and the flow field in the outer region and the particle motion is developed. A direct numerical simulation method using the finite element method is adopted to solve the model. The numerical results show that the presence of one particle influences the electric field and the flow field adjacent to the other particle and the particle motion, and that this influences weaken when the separation distance becomes bigger. The particle motion is dependent on its size, with the smaller particle moving a little faster. In addition, the zeta potential of particle has an effective influence on the particle motion. For a faster particle moving from behind a slower one, numerical results show that the faster moving particle will climb and then pass the slower moving particle then two particles’ centers are not located on a line parallel to the electric field.

Numerical and Experimental Studies on Electrical Potential Distribution of Pressure Driven Flow in Parallel Plate Microchannels

2004 ◽  
Author(s):  
Fuzhi Lu ◽  
Jun Yang ◽  
Daniel Y. Kwok
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Parallel Plate ◽  
Potential Distribution ◽  
Continuity Equation ◽  
Electrical Potential ◽  
Double Layers ◽  
Linear Potential ◽  
Pressure Driven Flow ◽  
Pressure Driven

A number of papers have been published on the computational approaches to electrokinetic flows. Nearly all of these decoupled approaches rely on the assumption of the Poisson-Boltzmann equation and do not consider the effect of velocity field on the electric double layers. By means of a charge continuity equation, we present here a numerical model for the simulation of pressure driven flow with electrokinetic effects in parallel-plate microchannels. Our approach is similar to that given by van Theemsche et al. [Anal. Chem., 74, 4919 (2002)] except that we assumed liquid conductivity to be constant and allows simulation to be performed in experimental dimension. The numerical simulation requires the solution of the Poisson equation, charge continuity equation and the incompressible Navier-Stokes equations. The simulation is implemented in a finite-volume based Matlab code. To validate the model, we measured the electrical potential downstream along the channel surface. The simulated results were also compared with known analytical solutions and experimental data. Results indicate that the linear potential distribution assumption in the streaming direction is in general not valid, especially when the flow rate is large for the specific channel geometry. The good agreement between numerical simulation and experimental data suggests that the present model can be employed to predict pressure-driven flow in microchannels.

scholarly journals Ion heating in the PISCES-RF liquid-cooled high-power, steady-state, helicon plasma device

2021 ◽  
Author(s):  
Saikat Chakraborty Thakur ◽  
Mitchell Paul ◽  
Eric M Hollmann ◽  
Elizabeth Lister ◽  
Earl E Scime ◽  
...  
Keyword(s):  
Steady State ◽  
High Power ◽  
Ion Heating ◽  
Helicon Plasma ◽  
Plasma Device

scholarly journals On-axis parallel ion speeds near mechanical and magnetic apertures in a helicon plasma device

2005 ◽  
Vol 12 (10) ◽  
pp. 103509 ◽  
Author(s):  
Xuan Sun ◽  
S. A. Cohen ◽  
Earl E. Scime ◽  
Mahmood Miah
Keyword(s):  
Helicon Plasma ◽  
Plasma Device ◽  
Axis Parallel

Numerical simulation of plasma double layers

1978 ◽  
Vol 20 (3) ◽  
pp. 391-404 ◽  
Author(s):  
Glenn Joyce ◽  
Richard F. Hubbard
Keyword(s):  
Numerical Simulation ◽  
Double Layer ◽  
Constant Velocity ◽  
Single Pulse ◽  
Potential Drop ◽  
Ion Beams ◽  
Spatial Extent ◽  
Double Layers ◽  
Limited Region ◽  
One Dimensional

The results of a numerical simulation of a plasma double layer are presented. The model is of a finite, one-dimensional plasma with a specified potential difference across the system. Initially a single pulse is formed which traverses the system with constant velocity. This stage is followed by the formation of a potential drop across a limited region of the plasma. The relation between the spatial extent of the double layer and the potential drop is given approximately by L = 6(edgr;φ/kTe)½. The double layer causes electron and ion beams which tend to lead to instabilities in the upstream and downstream regions.

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