Collisional effects in magnetized plasma sheath with two species of positive ions

• Published in: Journal of physics. D, Applied physics Vol. 42; no. 2; pp. 025204 - 025204 (6)
• Main Authors: Hatami, M M, Shokri, B, Niknam, A R
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 21.01.2009; Institute of Physics
• Subjects: Elementary processes in plasma; Exact sciences and technology; Magnetized plasmas; Magnetohydrodynamic and fluid equation; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Plasma interactions (nonlaser); Plasma properties; Plasma sheaths; Plasma simulation; Magnetized plasma; Ion collisions; Collisionless plasma; Theoretical study; Plasma collision processes; Density distribution; Plasma sheaths; Positive ions; Collisional plasma; Debye length; Numerical solution; Ion density; Collision frequency; Hydrodynamic model; Fluid models; Electron density; Electrostatic potential; Comparative study
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/42/2/025204

The effects of ion-neutral collision on the characteristics of a magnetized plasma sheath which consists of two species of positive ions are investigated. It is assumed that the ions have different masses. In contrast to our previous work, the effects of ion-neutral collision frequency are added to the magnetized plasma sheath. Using a three-fluid hydrodynamic model and some dimensionless variables, the dimensionless equations are obtained and solved numerically. By taking into account the ion-neutral collision effects on a magnetized three-component plasma sheath, it is shown that apart from the presence of the second ion species, by increasing the collision frequency of two ions with neutrals, the amplitude of fluctuations of ion species density distributions increases and the position of these fluctuations is shifted towards the plasma sheath edge. Also, by increasing the ion-neutral collision frequency these fluctuations turn off faster than those in a collisionless case. It is shown that in the collisional magnetized plasma sheath, the effects of the presence of the heavier ion species on the lighter ion density turn off much faster in comparison with what happens in a collisionless magnetized plasma sheath. Furthermore, it is found that in a collisionless plasma sheath by increasing the density of the heavier ion species, the normalized electrostatic potential decreases while in a collisional plasma sheath the presence of the heavier ion species does not have any considerable effect on the normalized electrostatic potential. In addition, it is shown that when the distance of each ion species from the plasma sheath boundary becomes larger than five times the electron Debye length (x > 5lambdaDe) the fluctuations of the ion species velocities disappear by increasing the ion-neutral collision frequency. Also, it is found that the electron density distribution decreases by increasing the ion-neutral collision frequency.