Preliminary investigation into laser high voltage interaction in the case of streamer-to-leader process using a high power CO2 laser

Abstract

This paper describes the preliminary small-scale experiments conducted in order to investigate the influence of intensely focused laser light produced by a CO2 laser on high voltage fields. The laser used operated at a maximum energy of 430 mJ per pulse and emitted in the far infrared region (10.6 µm). The pulse had a FWHM of 80 ns and a tail of 1 µs. Experiments were performed in order to obtain the minimum laser-induced break down voltage for specific spark gap arrangements (namely a coaxial and orthogonal gap of varying gap length. The results show that the orthogonal gap performed much better than the coaxial one. The minimum breakdown voltage that was obtained was for a 10 mm orthogonally orientated gap. For this case laser-induced breakdown strength was found to be 3 kV (11%of 27 kV).