Ion Temperature Effect on Bohm Criterion for Magnetized Plasma Sheath

Kaouini, Morad El; Chatei, Hassan; Driouch, I.; Hammouti, Mimoun El

doi:10.1007/s10894-010-9358-z

Cited by 15 publications

(18 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…36, using the assumption (9) is an oversimplification, but, nevertheless, this approach is widely used in the literature when sheath in an oblique magnetic field and with non-zero ion temperature is studied. [19][20][21]24,29,36 The coordinate system is illustrated in Fig. 2.…”

Section: Modelmentioning

confidence: 99%

“…The red line shows the solution of the system (27)-(31) for e ¼ 0.005, and the blue line displays the solution of the system (27)-(31) for e ¼ 0.002. Some authors [19][20][21][22][23][24]37 have studied the effects of finite ion temperature to the sheath in an oblique magnetic field using similar fluid model like ours. In majority of above mentioned papers, the problem is treated on the sheath scale of the asymptotic two-scale limit.…”

Section: -7mentioning

confidence: 99%

“…[19][20][21][22][23][24] Some authors analyzed the effects of the presence of two [25][26][27][28][29] or even multiple 30 species of positive ions. The sheath in a magnetized plasma in the presence of negative ions has been studied, [31][32][33][34][35] and even a combination of the presence of two positive and one negative ion species has been taken into account.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Fluid model of the sheath in front of a floating electrode immersed in a magnetized plasma with oblique magnetic field: Some comments on ion source terms and ion temperature effects

Gyergyek

Kovačič

2015

Physics of Plasmas

View full text Add to dashboard Cite

A one-dimensional fluid model of the magnetized plasma-wall transition region in front of a floating electrode immersed in a magnetized plasma with oblique magnetic field is presented. The Boltzmann relation is assumed for the electrons, while the positive ions obey the ion continuity and momentum exchange equation. The ions are assumed to be isothermal. By comparison with a twofluid model, it is shown that assuming the Boltzmann relation for the electrons implies that there is no creation or annihilation of the electrons. Consequently, there should not be any creation and annihilation of the positive ions either. The models that assume the Boltzmann relation for the electrons and a non-zero ion source term at the same time are therefore inconsistent, but such models have nevertheless been used extensively by many authors. So, in this work, an extensive comparison of the results obtained using the zero source term on one hand and three different non-zero source terms on the other hand is made. Four different ion source terms are considered in total: the zero source term and three different non-zero ion source terms. When the zero source term is used, the model becomes very sensitive to the boundary conditions, and in some cases, the solutions exhibit large amplitude oscillations. If any of the three non-zero ion source terms is used, those problems are eliminated, but also the consistency of the model is broken. The model equations are solved numerically in the entire magnetized plasma-wall transition region. For zero ion temperature, the model can be solved even if a very small ion velocity is selected as a boundary condition. For finite ion temperature, the system of equations becomes stiff, unless the ion velocity at the boundary is increased slightly above the ion thermal velocity. A simple method how to find a solution with a very small ion velocity at the boundary also for finite ion temperature in the entire magnetized plasma-wall transition region is proposed. V C 2015 AIP Publishing LLC.

show abstract

Section: Modelmentioning

confidence: 99%

Section: -7mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fluid model of the sheath in front of a floating electrode immersed in a magnetized plasma with oblique magnetic field: Some comments on ion source terms and ion temperature effects

Gyergyek

Kovačič

2015

Physics of Plasmas

View full text Add to dashboard Cite

show abstract

“…But the new Bohm criterion corresponds to a misinterpretation of sheath model according to the mathematical structure of boundary layer when the non-neutrality parameter q → 0. According to Liu et al (2003); ; El Kaouini et al (2011); Ghomi and Khoramabadi (2011);Ji et al (2011);and Hatami and Shokri (2012), for an electropositive plasma in collisional regime (β → ∞), with cold ions and no ionizations (q c = q and q i → 0), the velocity of positive ions at the sheath edge (u 0 = v +s /c s ) must be bounded by: (3.20b) or in the pre-sheath representation:…”

Section: Misinterpreted Bohm Criterion For Plasmas In Collisional Regimementioning

confidence: 99%

Examining the range of validity of the Bohm criterion

Crespo

Franklin

2014

J. Plasma Phys.

View full text Add to dashboard Cite

show abstract

“…Recently, many researchers have examined the behaviour of such sheath with an external oblique magnetic field, in the two collisionless [14,15] and collisional regimes [16,17]. Up to our knowledge, most of them, with the exception of the very recent work of Liu et al [14], do not considered the Ẽ Â B drift velocity which plays an important role in a magnetic confinement fusion device as pointed out by Krasheninnikov et al [18].…”

Section: Introductionmentioning

confidence: 99%

Combined Effect of Ion Temperature and Magnetic Field on Collisionless Sheath Structure

Kaouini

Chatei

2011

J Fusion Energ

View full text Add to dashboard Cite

A steady state two-fluid model has been used to study the characteristics of the collisionless plasma sheath in the presence of an external magnetic field and by taking into account both the ion temperature and the ion drift velocity at the sheath edge. The number and momentum equations of ions, the Boltzmann distribution of electrons and Poisson equations are solved numerically. The dependence of the Bohm magnetized sheath criterion to ion temperature is examined. It is shown that the ion temperature has significant effects on the sheath characteristics such as ion velocity, charged particles densities and electric potential. In the specific orientations of the magnetic field, it is found that by increasing the ion temperature, the ions do not achieve energy and the kinetic energy of the ions in the depth direction reaches the specific value at bigger distance from the plasma-sheath boundary.

show abstract

Ion Temperature Effect on Bohm Criterion for Magnetized Plasma Sheath

Cited by 15 publications

References 11 publications

Fluid model of the sheath in front of a floating electrode immersed in a magnetized plasma with oblique magnetic field: Some comments on ion source terms and ion temperature effects

Fluid model of the sheath in front of a floating electrode immersed in a magnetized plasma with oblique magnetic field: Some comments on ion source terms and ion temperature effects

Examining the range of validity of the Bohm criterion

Combined Effect of Ion Temperature and Magnetic Field on Collisionless Sheath Structure

Contact Info

Product

Resources

About