On the dynamic behavior of the anode-arc-root at the nozzle surface in a non-transferred plasma torch

Autores
Prevosto, L.; Risso, M.; Infante, D.; Cejas, E.; <div class="autor_fcen" id="4561">Kelly, H.</div>; Mancinelli, B.
Año de publicación
2012
Idioma
inglés
Tipo de recurso
artículo
Estado
Versión publicada
Descripción
The dynamic behavior of the anode-arc-root at the nozzle surface of a plasma torch was experimentally investigated in this work. A gas (N2) vortex-stabilized non-transferred arc torch with a thoriated tungsten rod (2wt %) cathode (3.2 mm diameter) and a coaxial anode (5 mm diameter, 30 mm length) was used in the experiment. By using a sweeping Langmuir probe in floating condition, the voltage of the plasma jet outside the nozzle was inferred. Arc voltage waveforms were also obtained. Data have been obtained for an arc current of 100 A and a gas flow rate of 30 Nl min-1. A typical sawtooth shape (i.e., restrike mode) (with a fluctuating level of ≈ ± 25 %) and a dominant frequency of ≈ 6.5 kHz was observed in the arc voltage waveforms, which is attributed to anode-arc-root movements along the anode surface followed by a restrike at a certain point close to the cathode. By performing a time correlation between the probe and arc voltage oscillograms together with simple estimations, the amplitude of the movement of the arc-root along the anode surface as well its velocity were inferred.
Fil:Kelly, H. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fuente
J. Phys. Conf. Ser. 2012;370(1)
Materia
Anode surfaces
Arc current
Arc voltage
Dominant frequency
Dynamic behaviors
Floating conditions
Nozzle surface
Thoriated tungsten
Time correlations
Cathodes
Tungsten
Plasma torches
Nivel de accesibilidad
Acceso abierto
Licencia
http://creativecommons.org/licenses/by/2.5/ar
Repositorio
Biblioteca Digital (UBA-FCEN)
Institución
Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales
OAI Identificador
snrd:HASH01a6f1d2352f58fdd6d1f91c