Model for arc cathode region in a wide pressure range

Nielsen, Torbjørn Kristian; Kaddani, Ahmed; Benilov, M. S.

doi:10.1088/0022-3727/34/13/312

Cited by 9 publications

(4 citation statements)

References 13 publications

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“…In this work, the near-cathode plasma layer is calculated by means of a model similar to the model [22]. The latter model was developed for a plasma in the range of pressures of the order of 1 atm and has been used in a wide range of environments for both analytical treatment and numerical modelling [12,22,[29][30][31]. In this work, modifications are introduced into the model [22] on the basis of results of recent studies.…”

Section: Solution On the Plasma Sidementioning

confidence: 99%

Heating of refractory cathodes by high-pressure arc plasmas: I

Benilov

Cunha

2002

J. Phys. D: Appl. Phys.

214

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A model of the near-cathode plasma layer in a plasma under a pressure of the order of one or several bars is reconsidered on the basis of recent theoretical results. Physics of the near-cathode layer is analysed in the range of near-cathode voltage drops of up to 50 V, in accord to recent experimental results which have shown that the near-cathode voltage drop in high-pressure arc discharges may be that high. It is found that a non-monotony of the dependence of the energy flux density on the surface temperature at fixed values of the near-cathode voltage drop is caused by one of the three mechanisms: overcoming of the increase of combined ion and plasma electron heating by the increase of thermionic cooling as the plasma approaches full ionization; non-monotony of the dependence of the ion current on the electron temperature which is caused by the deviation of the ion current from the diffusion value; rapid increase of the plasma electron heating which is subsequently overcome by thermionic cooling. A closed description of the plasma-cathode interaction is obtained by numerically solving the nonlinear boundary-value problem for the temperature distribution inside the cathode body. Results of numerical modelling of the diffuse discharge under conditions of a model arc lamp are given and a good agreement with the experimental data is shown.

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Section: Solution On the Plasma Sidementioning

confidence: 99%

Heating of refractory cathodes by high-pressure arc plasmas: I

Benilov

Cunha

2002

J. Phys. D: Appl. Phys.

214

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“…where κ s is the heat conductivity of the electrode material, q a,c denotes the effective flux from the plasma to the anode/cathode and the second term on the right hand side describes the heat loss due to evaporation. The flux of evaporated atoms with a mass m v is obtained according to the Langmuir equation [29] as…”

Section: Melting and Evaporationmentioning

confidence: 99%

“…where p v is the equilibrium pressure of the metal vapour at temperature of the wall T w . Its value is taken as [29] p v = 133.3[Pa]T −1.27 w 10 13.39−17656/Tw (10) The latent heat of evaporation L is expressed through the boiling T b and critical T cr temperatures [29]:…”

Section: Melting and Evaporationmentioning

confidence: 99%

Unified modelling of low-current short-length arcs between copper electrodes

Baeva¹,

Boretskij²,

González³

et al. 2020

J. Phys. D: Appl. Phys.

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In this work, we present for the first time a unified model of a low-current short-length arc between copper electrodes. The model employs one-dimensional fluid description of the plasma in argon and copper vapour at atmospheric pressure and the heat transfer in the electrodes made of copper. The solution of the particle and energy conservation of electrons and heavy particles is coupled with the solution of the Poisson equation, from which the self-consistent electric field is obtained. The operation of the non-refractory cathode is based on thermo-field emission. Heat fluxes from the plasma to the electrodes are considered so that a phase change and evaporation from the cathode and a release of copper atoms into the plasma are taken into account. The influence of the copper atoms and ions on the plasma properties is analysed and discussed. The model’s predictions are compared with experimental data and a qualitative agreement is obtained besides the restrictions of the one-dimensional fluid model.

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“…In this paper, the near-cathode phenomena are discussed along the lines of the model [14]. Note that this model has been tested in different environments [14][15][16]19,20]; a similar model was employed in [17].…”

Section: Is the Presence Of The Space-charge Sheath Important?mentioning

confidence: 99%

Theory and modelling of arc cathodes

Benilov

2002

Plasma Sources Sci. Technol.

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Understanding of cathode phenomena in arc discharges has considerably improved in recent years due to the progress both in experiment and in theory. A review of the present understanding of cathode phenomena in high-pressure arc discharges is given. The effect of processes in the arc column on the cathode part of the discharge in most cases is weak, which is a consequence of the fact that the energy flux coming to the cathode is formed in a thin near-cathode plasma region. A theoretical model of the near-cathode region is described. The model can be used both by itself or as a part of a code modelling the whole system of arc electrodes. In particular, the model results in a simple estimate of the upper limit of the cathode temperature and of the lower limit of the temperature inside a cathode spot. A simple asymptotic solution to the thermal conduction equation in the cathode body, describing a steady-state cathode spot, may be obtained making use of the fact that the energy flux from the plasma to the cathode surface is localized in a narrow temperature range. Approaches to a self-consistent modelling of diffuse and spot modes of current transfer to the cathode are discussed.

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Model for arc cathode region in a wide pressure range

Cited by 9 publications

References 13 publications

Heating of refractory cathodes by high-pressure arc plasmas: I

Heating of refractory cathodes by high-pressure arc plasmas: I

Unified modelling of low-current short-length arcs between copper electrodes

Theory and modelling of arc cathodes

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