Investigation of the relevant kinetic processes in the initial stage of a double-arcing instability in oxygen plasmas
A numerical investigation of the kinetic processes in the initial (nanosecond range) stage of the double-arcing instability was developed. The plasma-sheath boundary region of an oxygen-operated cutting torch was considered. The energy balance and chemistry processes in the discharge were described....
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2018
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_1070664X_v25_n5_p_Mancinelli http://hdl.handle.net/20.500.12110/paper_1070664X_v25_n5_p_Mancinelli |
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paper:paper_1070664X_v25_n5_p_Mancinelli2023-06-08T16:04:42Z Investigation of the relevant kinetic processes in the initial stage of a double-arcing instability in oxygen plasmas Electric discharges Excited states Field emission Heating rate Oxygen Oxygen cutting Plasma diagnostics Plasma sheaths Thermodynamic stability Critical electric field Emission instabilities Excited electronic state Fast electronics Nanosecond range Numerical investigations Thermal instabilities Translational energy Plasma stability A numerical investigation of the kinetic processes in the initial (nanosecond range) stage of the double-arcing instability was developed. The plasma-sheath boundary region of an oxygen-operated cutting torch was considered. The energy balance and chemistry processes in the discharge were described. It is shown that the double-arcing instability is a sudden transition from a diffuse (glow-like) discharge to a constricted (arc-like) discharge in the plasma-sheath boundary region arising from a field-emission instability. A critical electric field value of ∼107 V/m was found at the cathodic part of the nozzle wall under the conditions considered. The field-emission instability drives in turn a fast electronic-to-translational energy relaxation mechanism, giving rise to a very fast gas heating rate of at least ∼109 K/s, mainly due to reactions of preliminary dissociation of oxygen molecules via the highly excited electronic state O2(B3Σu -) populated by electron impact. It is expected that this fast oxygen heating rate further stimulates the discharge contraction through the thermal instability mechanism. © 2018 Author(s). 2018 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_1070664X_v25_n5_p_Mancinelli http://hdl.handle.net/20.500.12110/paper_1070664X_v25_n5_p_Mancinelli |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Electric discharges Excited states Field emission Heating rate Oxygen Oxygen cutting Plasma diagnostics Plasma sheaths Thermodynamic stability Critical electric field Emission instabilities Excited electronic state Fast electronics Nanosecond range Numerical investigations Thermal instabilities Translational energy Plasma stability |
| spellingShingle |
Electric discharges Excited states Field emission Heating rate Oxygen Oxygen cutting Plasma diagnostics Plasma sheaths Thermodynamic stability Critical electric field Emission instabilities Excited electronic state Fast electronics Nanosecond range Numerical investigations Thermal instabilities Translational energy Plasma stability Investigation of the relevant kinetic processes in the initial stage of a double-arcing instability in oxygen plasmas |
| topic_facet |
Electric discharges Excited states Field emission Heating rate Oxygen Oxygen cutting Plasma diagnostics Plasma sheaths Thermodynamic stability Critical electric field Emission instabilities Excited electronic state Fast electronics Nanosecond range Numerical investigations Thermal instabilities Translational energy Plasma stability |
| description |
A numerical investigation of the kinetic processes in the initial (nanosecond range) stage of the double-arcing instability was developed. The plasma-sheath boundary region of an oxygen-operated cutting torch was considered. The energy balance and chemistry processes in the discharge were described. It is shown that the double-arcing instability is a sudden transition from a diffuse (glow-like) discharge to a constricted (arc-like) discharge in the plasma-sheath boundary region arising from a field-emission instability. A critical electric field value of ∼107 V/m was found at the cathodic part of the nozzle wall under the conditions considered. The field-emission instability drives in turn a fast electronic-to-translational energy relaxation mechanism, giving rise to a very fast gas heating rate of at least ∼109 K/s, mainly due to reactions of preliminary dissociation of oxygen molecules via the highly excited electronic state O2(B3Σu -) populated by electron impact. It is expected that this fast oxygen heating rate further stimulates the discharge contraction through the thermal instability mechanism. © 2018 Author(s). |
| title |
Investigation of the relevant kinetic processes in the initial stage of a double-arcing instability in oxygen plasmas |
| title_short |
Investigation of the relevant kinetic processes in the initial stage of a double-arcing instability in oxygen plasmas |
| title_full |
Investigation of the relevant kinetic processes in the initial stage of a double-arcing instability in oxygen plasmas |
| title_fullStr |
Investigation of the relevant kinetic processes in the initial stage of a double-arcing instability in oxygen plasmas |
| title_full_unstemmed |
Investigation of the relevant kinetic processes in the initial stage of a double-arcing instability in oxygen plasmas |
| title_sort |
investigation of the relevant kinetic processes in the initial stage of a double-arcing instability in oxygen plasmas |
| publishDate |
2018 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_1070664X_v25_n5_p_Mancinelli http://hdl.handle.net/20.500.12110/paper_1070664X_v25_n5_p_Mancinelli |
| _version_ |
1768545104791863296 |