Langmuir probe measurements in a time-fluctuating-highly ionized non-equilibrium cutting arc: Analysis of the electron retarding part of the time-averaged current-voltage characteristic of the probe
This work describes the application of Langmuir probe diagnostics to the measurement of the electron temperature in a time-fluctuating-highly ionized, non-equilibrium cutting arc. The electron retarding part of the time-averaged current-voltage characteristic of the probe was analysed, assuming that...
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2013
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00346748_v84_n12_p_Prevosto http://hdl.handle.net/20.500.12110/paper_00346748_v84_n12_p_Prevosto |
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paper:paper_00346748_v84_n12_p_Prevosto2023-06-08T15:00:53Z Langmuir probe measurements in a time-fluctuating-highly ionized non-equilibrium cutting arc: Analysis of the electron retarding part of the time-averaged current-voltage characteristic of the probe Kelly, Héctor Juan Collision-free plasma Electron currents Exponential expression Fluctuation analysis Langmuir probe diagnostics Langmuir probe measurements Local thermal equilibrium Plasma fluctuations Ionization Langmuir probes Probes Electron temperature This work describes the application of Langmuir probe diagnostics to the measurement of the electron temperature in a time-fluctuating-highly ionized, non-equilibrium cutting arc. The electron retarding part of the time-averaged current-voltage characteristic of the probe was analysed, assuming that the standard exponential expression describing the electron current to the probe in collision-free plasmas can be applied under the investigated conditions. A procedure is described which allows the determination of the errors introduced in time-averaged probe data due to small-amplitude plasma fluctuations. It was found that the experimental points can be gathered into two well defined groups allowing defining two quite different averaged electron temperature values. In the low-current region the averaged characteristic was not significantly disturbed by the fluctuations and can reliably be used to obtain the actual value of the averaged electron temperature. In particular, an averaged electron temperature of 0.98 ± 0.07 eV (= 11400 ± 800 K) was found for the central core of the arc (30 A) at 3.5 mm downstream from the nozzle exit. This average included not only a time-average over the time fluctuations but also a spatial-average along the probe collecting length. The fitting of the high-current region of the characteristic using such electron temperature value together with the corrections given by the fluctuation analysis showed a relevant departure of local thermal equilibrium in the arc core. © 2013 AIP Publishing LLC. Fil:Kelly, H. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2013 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00346748_v84_n12_p_Prevosto http://hdl.handle.net/20.500.12110/paper_00346748_v84_n12_p_Prevosto |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Collision-free plasma Electron currents Exponential expression Fluctuation analysis Langmuir probe diagnostics Langmuir probe measurements Local thermal equilibrium Plasma fluctuations Ionization Langmuir probes Probes Electron temperature |
| spellingShingle |
Collision-free plasma Electron currents Exponential expression Fluctuation analysis Langmuir probe diagnostics Langmuir probe measurements Local thermal equilibrium Plasma fluctuations Ionization Langmuir probes Probes Electron temperature Kelly, Héctor Juan Langmuir probe measurements in a time-fluctuating-highly ionized non-equilibrium cutting arc: Analysis of the electron retarding part of the time-averaged current-voltage characteristic of the probe |
| topic_facet |
Collision-free plasma Electron currents Exponential expression Fluctuation analysis Langmuir probe diagnostics Langmuir probe measurements Local thermal equilibrium Plasma fluctuations Ionization Langmuir probes Probes Electron temperature |
| description |
This work describes the application of Langmuir probe diagnostics to the measurement of the electron temperature in a time-fluctuating-highly ionized, non-equilibrium cutting arc. The electron retarding part of the time-averaged current-voltage characteristic of the probe was analysed, assuming that the standard exponential expression describing the electron current to the probe in collision-free plasmas can be applied under the investigated conditions. A procedure is described which allows the determination of the errors introduced in time-averaged probe data due to small-amplitude plasma fluctuations. It was found that the experimental points can be gathered into two well defined groups allowing defining two quite different averaged electron temperature values. In the low-current region the averaged characteristic was not significantly disturbed by the fluctuations and can reliably be used to obtain the actual value of the averaged electron temperature. In particular, an averaged electron temperature of 0.98 ± 0.07 eV (= 11400 ± 800 K) was found for the central core of the arc (30 A) at 3.5 mm downstream from the nozzle exit. This average included not only a time-average over the time fluctuations but also a spatial-average along the probe collecting length. The fitting of the high-current region of the characteristic using such electron temperature value together with the corrections given by the fluctuation analysis showed a relevant departure of local thermal equilibrium in the arc core. © 2013 AIP Publishing LLC. |
| author |
Kelly, Héctor Juan |
| author_facet |
Kelly, Héctor Juan |
| author_sort |
Kelly, Héctor Juan |
| title |
Langmuir probe measurements in a time-fluctuating-highly ionized non-equilibrium cutting arc: Analysis of the electron retarding part of the time-averaged current-voltage characteristic of the probe |
| title_short |
Langmuir probe measurements in a time-fluctuating-highly ionized non-equilibrium cutting arc: Analysis of the electron retarding part of the time-averaged current-voltage characteristic of the probe |
| title_full |
Langmuir probe measurements in a time-fluctuating-highly ionized non-equilibrium cutting arc: Analysis of the electron retarding part of the time-averaged current-voltage characteristic of the probe |
| title_fullStr |
Langmuir probe measurements in a time-fluctuating-highly ionized non-equilibrium cutting arc: Analysis of the electron retarding part of the time-averaged current-voltage characteristic of the probe |
| title_full_unstemmed |
Langmuir probe measurements in a time-fluctuating-highly ionized non-equilibrium cutting arc: Analysis of the electron retarding part of the time-averaged current-voltage characteristic of the probe |
| title_sort |
langmuir probe measurements in a time-fluctuating-highly ionized non-equilibrium cutting arc: analysis of the electron retarding part of the time-averaged current-voltage characteristic of the probe |
| publishDate |
2013 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00346748_v84_n12_p_Prevosto http://hdl.handle.net/20.500.12110/paper_00346748_v84_n12_p_Prevosto |
| work_keys_str_mv |
AT kellyhectorjuan langmuirprobemeasurementsinatimefluctuatinghighlyionizednonequilibriumcuttingarcanalysisoftheelectronretardingpartofthetimeaveragedcurrentvoltagecharacteristicoftheprobe |
| _version_ |
1768544993573601280 |