Electrical Breakdown in Gaseous Nitrogen at Cryogenic Temperature with a Heated Tape Electrode

With the objective to better understand and design the electrical insulation of resistive superconducting fault current limiters (r-SCFCL), breakdown experiments were performed in liquid (LN
2
), and gaseous (LN
2
) nitrogen. Conditions relevant to the extreme case of severe boiling, occurring during superconducting/resistive transition, were chosen. A tape-shaped electrode rapidly heated by impulse Joule effect is used to closely represent the specific conditions occurring during the transition. Comparisons with previous experiments carried out in LN
2
show that the reduction of breakdown voltage during transition results from the replacement of LN
2
by GN
2
, and from heating of GN
2
. Breakdown voltages in GN
2
with divergent tape-plane geometry can be modelled using the streamer criterion.