Ylm. Creyghton et al., DIAGNOSTIC-TECHNIQUES FOR ATMOSPHERIC STREAMER DISCHARGES, IEE proceedings. A, Science, measurement and technology, 141(2), 1994, pp. 141-147
Fast electrical and optical diagnostics are required for the analysis
of atmospheric streamer discharges. This is illustrated for the case o
f positive streamer corona produced along wire electrodes by high volt
age pulses with rise times of tens of nanoseconds. Electrical measurem
ents with a high time resolution reveal the energy input in two discha
rge phases (primary and secondary streamer). The discharge structure i
s visualised using a gated image intensifier. The number of streamers
per unit length of anode wire and the streamer diameter are determined
. The streamer velocity is measured with a time-of-flight method using
two optical fibres. Time-resolved spectroscopic measurements of the i
ntensity ratio of N2+ and N2 emission lines reveal that the average el
ectron energy in the primary streamer phase is significantly higher th
an in the subsequent secondary streamer. The neutral gas temperature i
n the discharge is determined from the rotational structure of an N2 e
mission line and is only slightly above the background gas temperature
. Schlieren photographs visualise the heat dissipated in residual stre
amer channels.