Time evolution of ion-acoustic double layers in an unmagnetized plasma

2008 ◽  
Vol 15 (8) ◽  
pp. 082304 ◽  
Author(s):  
R. Bharuthram ◽  
E. Momoniat ◽  
F. Mahomed ◽  
S. V. Singh ◽  
M. K. Islam
Keyword(s):  
Time Evolution ◽  
Double Layers ◽  
Ion Acoustic ◽  
Unmagnetized Plasma ◽  
Ion Acoustic Double Layers

Large-amplitude ion-acoustic double layers in multispecies plasma

1990 ◽  
Vol 68 (6) ◽  
pp. 474-478 ◽  
Author(s):  
S. L. Jain ◽  
R. S. Tiwari ◽  
S. R. Sharma
Keyword(s):  
Large Amplitude ◽  
Reductive Perturbation Method ◽  
Negative Ion ◽  
Double Layers ◽  
Ion Acoustic ◽  
Unmagnetized Plasma ◽  
Ion Acoustic Double Layers ◽  
Ion Species ◽  
Ion Impurity ◽  
Positive Ion

We have investigated the effect of second-ion species on the characteristics of a large-amplitude ion-acoustic double layers (IADL) in a collisionless, unmagnetized plasma consisting of hot and cold Maxwellian populations of electrons and two cold-ion species with different masses, concentrations, and charge states. After deriving the criteria for the existence of large-amplitude IADL, we find that the presence of a positive-ion impurity does not modify considerably the characteristics of large-amplitude IADL. However, the presence of a negative-ion impurity changes significantly the characteristics of large-amplitude IADL. We have also presented an analytic discussion of small-amplitude IADL using a reductive perturbation method.

Ion acoustic double layers forming behind irradiated solid objects in streaming plasmas

2010 ◽  
Vol 76 (3-4) ◽  
pp. 429-439 ◽  
Author(s):  
W. J. MILOCH ◽  
V. L. REKAA ◽  
H. L. PÉCSELI ◽  
J. TRULSEN
Keyword(s):  
Numerical Simulations ◽  
Uv Light ◽  
Three Dimensional ◽  
Double Layers ◽  
Back Side ◽  
Electron Population ◽  
Von Neumann ◽  
Solid Objects ◽  
Ion Acoustic ◽  
Ion Acoustic Double Layers

AbstractSmall solid metallic objects in relative motion to thermal plasmas are studied by numerical simulations. We analyze supersonic motions, where a distinctive ion wake is formed behind obstacles. At these plasma drift velocities, ions enter the wake predominantly due to deflections by the electric field in the sheath around the obstacle. By irradiating the back side of the object by ultraviolet (UV) light, we can induce also an enhanced photo-electron population there. The resulting charge distribution gives rise to a pronounced local potential and plasma density well behind the object. This potential variation has the form of a three-dimensional ion acoustic double layer, containing also an ion phase space vortex. The analysis is supported also by one-dimensional numerical simulations to illustrate the importance of boundary conditions, Dirichlet and von Neumann conditions in particular.

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