Static and recovery characteristics of wall-stabilized d.c. arcs in nitrogen

Abstract

Measurements are given of the field gradient characteristics for arcs operating in tubes of different diameters in nitrogen. The recoveries of conductance for these tubes (diameters 4, 5 and 7 mm) are also given over a period of 300 μs following rapid interruption (1 μs). The arc behaviour under imposed gas flow conditions of 0-2·5 1. min−1 is also described. In particular it is found that the recovery, when presented as a log conductance against time plot, has three linear regions. Time constants derived from these linear portions do not seem to exhibit a simple dependence on the confining tube radius and are at variance with previous theories.A solution of the energy balance equation is also given, for conditions of variable thermal diffusivity combined with a non-linear relationship between the electrical conductivity and heat potential functions, and this gives close agreement with the experimental data.