Investigation of plasma flow in vacuum arc with hot cathode

Амиров, Р. Х.; Vorona, N. A.; Gavrikov, A. V.; Lizyakin, G; Polistchook, V.P.; Samoylov, I. S.; Smirnov, V. S.; Usmanov, R. A.; Yartsev, I. M.

doi:10.1088/1742-6596/550/1/012014

Cited by 3 publications

(8 citation statements)

References 7 publications

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“…GADOLINIUM CATHODE A significant amount of experimental data on spotless vacuum arc attachment has been obtained for cathodes made of gadolinium [2]- [4], [6], [7]. The value of work function recommended in [21] for a polycrystalline surface of gadolinium is 3.1 eV, i.e., quite low, and a still lower value of 2.9 eV is given in [23].…”

Section: Chromium Cathodementioning

confidence: 99%

“…The value of work function recommended in [21] for a polycrystalline surface of gadolinium is 3.1 eV, i.e., quite low, and a still lower value of 2.9 eV is given in [23]. Accordingly, it is well known that thermionic emission current is high enough to ensure the spotless attachment of vacuum arcs to a gadolinium cathode observed in the experiments [2]- [4], [6], [7]. However, it is of interest to apply to gadolinium cathodes the same approach that was applied above to cathodes made of chromium, to once again validate the approach and demonstrate the possibility of self-consistent calculation of some parameters of the spotless vacuum arc on a gadolinium cathode.…”

Section: Chromium Cathodementioning

confidence: 99%

“…It should be stressed that the smallness of j i is not a consequence of the return of most part of evaporated atoms to the cathode in the form of ions; e.g., for T w = 2000 K about 43% of the ions are produced after the potential maximum in the sheath and escape into the plasma. Rather, the smallness of the contribution of the ion current originates in the well known [2]- [4], [6], [7] fact that the flux of emitted electrons from a gadolinium surface is significantly higher than the flux of evaporated atoms, which results from the low work function of gadolinium and relatively high evaporation energy. (The latter equals 3.73 eV per atom [22]; for comparison, values for Cr and Cu are 3.55 and 3.16 eV, respectively [24].…”

Section: Chromium Cathodementioning

confidence: 99%

“…Therefore, a possible source of heating of gadolinium cathodes in the experiments [2]- [4], [6], [7] is radiation from the plasma.…”

Section: Chromium Cathodementioning

confidence: 99%

“…Characteristic features of this discharge are a relatively low current density at the cathode, of the order of 10 5 -10 6 A · m −2 , and the ability to generate steady highly ionized plasma containing no microdroplet fraction. The latter feature may be attractive for applications [6], [7].…”

Section: Introductionmentioning

confidence: 99%

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Physics of Spotless Mode of Current Transfer to Cathodes of Metal Vapor Arcs

Benilov

Benilova

2015

IEEE Trans. Plasma Sci.

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A fresh attempt is made to clarify the physics of the diffuse, or spotless, mode of current transfer that may occur on cathodes of vacuum arcs if the average cathode surface temperature is high enough, about 2000 K. It is shown that in the case of chromium cathode the usual mechanism of current transfer to arc cathodes cannot sustain current densities of the order of 10 5 -10 6 A · m −2 observed in the experiment, the reason being that the electrical power deposited into electron gas in the nearcathode space-charge sheath is insufficient. It is hypothesized that the electrical power is supplied to the electron gas primarily in the bulk plasma, rather than in the sheath, and a high level of electron energy in the vicinity of the sheath edge is sustained by electron heat conduction from the bulk plasma. Estimates of the current of ions diffusing to the sheath edge from the quasineutral plasma gave values comparable with the experimental current density, which supports the above hypothesis. On the contrary, the spotless attachment of vacuum arcs to gadolinium cathodes may be interpreted as a manifestation of the usual mechanism of current transfer to arc cathodes. Results given for gadolinium cathodes by a model of near-cathode layers in vacuum arcs conform to available experimental information.

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Section: Chromium Cathodementioning

confidence: 99%

Section: Chromium Cathodementioning

confidence: 99%

Section: Chromium Cathodementioning

confidence: 99%

“…Therefore, a possible source of heating of gadolinium cathodes in the experiments [2]- [4], [6], [7] is radiation from the plasma.…”

Section: Chromium Cathodementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Physics of Spotless Mode of Current Transfer to Cathodes of Metal Vapor Arcs

Benilov

Benilova

2015

IEEE Trans. Plasma Sci.

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Determination of the degree of ionization of vapors of conducting and dielectric materials during electron-beam evaporation in the forevacuum range of pressure

Tyunkov

Andronov

Окс

et al. 2023

Vacuum

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Multiple solutions in the theory of dc glow discharges and cathodic part of arc discharges. Application of these solutions to the modeling of cathode spots and patterns: a review

Benilov

2014

Plasma Sources Sci. Technol.

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A new class of stationary solutions in the theory of glow discharges and plasma-cathode interaction in ambient-gas arc discharges has been found over the past 15 years. These solutions exist simultaneously with the solution given in textbooks, which describes a discharge mode with a uniform or smooth distribution of current over the cathode surface, and describes modes with various configurations of cathode spots: normal spots on glow cathodes, patterns of multiple spots recently observed on cathodes of glow microdischarges and spots on arc cathodes. In particular, these solutions show that cathode spots represent a manifestation of self-organization caused by basic mechanisms of the near-cathode space-charge sheath; another illustration of the richness of the gas discharge science. As far as arc cathodes are concerned, the new solutions have proved relevant for industrial applications. This work is dedicated to reviewing the multiple solutions obtained to date, their systematization, and analysis of their properties and physical meaning. The treatment is performed in the context of general trends of self-organization in bistable nonlinear dissipative systems, which allows one to consider glow discharges or arc-cathode interaction within a single physically transparent framework without going into mathematical details and offers a possibility of systematic computation of the multiple solutions. Relevant computational aspects and experimental data are discussed.

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Investigation of plasma flow in vacuum arc with hot cathode

Cited by 3 publications

References 7 publications

Physics of Spotless Mode of Current Transfer to Cathodes of Metal Vapor Arcs

Physics of Spotless Mode of Current Transfer to Cathodes of Metal Vapor Arcs

Determination of the degree of ionization of vapors of conducting and dielectric materials during electron-beam evaporation in the forevacuum range of pressure

Multiple solutions in the theory of dc glow discharges and cathodic part of arc discharges. Application of these solutions to the modeling of cathode spots and patterns: a review

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