Sheath criterion in constant mean free path collisional plasma with two distinct temperature q-nonextensive electrons

Borgohain, Dima Rani; Saharia, K.

doi:10.1007/s12648-018-1263-8

Cited by 5 publications

(4 citation statements)

References 33 publications

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“…The magnitude of c +0 cannot continue to decrease because of the upper limit of the positive ion velocity at the sheath edge (please see equation (15)). This behaviour is in agreement with the results of other researchers also [13,54].…”

Section: Resultssupporting

confidence: 94%

Modelling of electronegative collisional warm plasma for plasma-surface interaction process

Dhawan

Malik

2021

Plasma Sci. Technol.

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An electronegative collisional plasma having warm and massive positive ions, non-extensive distributed electrons and Boltzmann distributed negative ions is modelled for the plasma-surface interaction process that is used for the surface nitriding. Specifically the sheath formation is evaluated through the Bohm’s criterion, which is found to be modified, and the variation of the sheath thickness and profiles of the density of plasma species and the net space charge density in the sheath region in addition to the electric potential. The effect of ion temperature, non-extensivity and collisional parameter is examined in greater detail considering the collisional cross-section to obey power-law dependency on the positive ion velocity. The positive ions are found to enter in the sheath region at lower velocities in the collisional plasma compared to the case of collision-less plasma; this velocity sees minuscule reduction with increasing non-extensivity. The increasing ion temperature and collisional parameter lead to the formation of sheath with smaller thickness.

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Section: Resultssupporting

confidence: 94%

Modelling of electronegative collisional warm plasma for plasma-surface interaction process

Dhawan

Malik

2021

Plasma Sci. Technol.

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“…The combination of such multi-component plasmas with magnetic field magnetization also adds difficulties to the analysis of plasma sheath properties. Many researchers have studied the plasma sheath structure by assuming two species of electrons having different temperatures through theoretical studies and numerical simulations [32][33][34][35]. Research on the non-Maxwellian distribution of two-temperature electrons has not yet been sufficiently conducted.…”

Section: Introductionmentioning

confidence: 99%

Properties of collisional plasma sheath with ionization source term and two-temperature electrons in an oblique magnetic field

Chen,

An,

Tan

et al. 2024

J. Phys. D: Appl. Phys.

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A collisional magnetized plasma sheath with two groups of electrons has been studied using a fluid model including the effects of the ionization source term and the collisional force between ions and neutral atoms. Two kinds of non-Maxwellian descriptions of electron velocity distribution, non-extensive distribution and truncated distribution, are applied in the model, and the ionization effects of both kinds are considered. By applying Sagdeev potential, the modified Bohm sheath criterion is derived. The effects of ionization, magnetic field, and high-temperature electron concentration ratio on plasma sheath density, potential, sheath thickness, and ion kinetic energy are studied. In cases with high background gas density, ion density accumulates at the sheath edge position, forming a peak and manifesting as a rapid drop in the potential profile. The distribution characteristics of electrons have a significant impact on the transport properties of ions. Oscillations and non-monotonic characteristics of net charge near the sheath edge occur as the magnetic field angle increases, leading to an increase in the sheath layer width. It can be seen that in the case of a collisional sheath structure with high-temperature electrons, it is essential to consider the sheath changes induced by the ionization and the collisional force. Compared to a symmetric electron velocity distribution, the actual thickness of the sheath layer in a truncated electron distribution assumption could be significantly reduced.

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“…A good number of studies have been carried out to explore sheath physics by assuming non‐extensive electron distribution. [ 25–30 ] These studies have reported that deviation of electron distribution from the Boltzmannian nature leads to variations in the space charge deposition near the wall. Moreover, expansion of the sheath has also been observed for lower values of

q

.…”

Section: Introductionmentioning

confidence: 99%

Secondary electron emission and collisional effects in a two‐electron temperature plasma sheath

Sharma

Paul

Deka

et al. 2023

Contributions to Plasma Physics

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The effects of secondary electron emission from the surface of a material that is in direct contact with a plasma containing two different electron groups have been investigated based on the hydro‐dynamic sheath model. The two‐electron groups present in the system have distinct densities and temperatures. They are described by the non‐extensive distribution function, whereas cold ions are assumed to be fluid elements. In addition, the effect of ion‐neutral collision has also been taken into account. The study reveals that the electron non‐extensivity has a significant effect on the secondary electron population as well as space charge deposition near the wall. The results obtained from the study will provide a better understanding of the plasma‐wall transition region under an electron‐emitting condition.

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Sheath criterion in constant mean free path collisional plasma with two distinct temperature q-nonextensive electrons

Cited by 5 publications

References 33 publications

Modelling of electronegative collisional warm plasma for plasma-surface interaction process

Modelling of electronegative collisional warm plasma for plasma-surface interaction process

Properties of collisional plasma sheath with ionization source term and two-temperature electrons in an oblique magnetic field

Secondary electron emission and collisional effects in a two‐electron temperature plasma sheath

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