On the dynamics of the space-charge layer inside the nozzle of a cutting torch and its relation with the "non-destructive" double-arcing phenomenon

Autores
Prevosto, L.; <div class="autor_fcen" id="4561">Kelly, H.</div>; Mancinelli, B.
Año de publicación
2011
Idioma
inglés
Tipo de recurso
artículo
Estado
Versión publicada
Descripción
Experimental observations on the plasma dynamics inside the nozzle of a 30 A oxygen cutting torch operated at conditions close to the double arcing are reported. It is employed a technique previously developed in our laboratory consisting in using the nozzle as a large-sized Langmuir probe. Based on the behavior of the ion current signal and simple estimations, it is concluded that (1) the non-equilibrium plasma inside the nozzle is far from the steady state in time, in contrast to what is frequently assumed. The power supply ripple was identified as the main fluctuations source and (2) large-scale plasma fluctuations inside the nozzle could cause transient (total duration of the order of 100 μs) Townsend avalanches developing in the space-charge layer located between the arc plasma and the nozzle wall. Such events trigger the so called non-destructive double-arcing phenomena without appealing to the presence of insulating films deposited inside the nozzle orifice, as was previously proposed in the literature. © 2011 American Institute of Physics.
Fil:Kelly, H. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fuente
J Appl Phys 2011;110(8)
Materia
Arc plasma
Cutting torch
Experimental observation
Insulating film
Ion-current signal
Non destructive
Nonequilibrium plasmas
Nozzle orifice
Nozzle wall
Plasma dynamics
Plasma fluctuations
Power supply
Space charges
Steady state
Dynamics
Oxygen cutting
Plasma diagnostics
Plasmas
Nozzles
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:HASHe1044018ea06eb482979c3