The influence of electron density on the formation of streamers in electrical discharges triggered with ultrashort laser pulses

• Published in: IEEE transactions on plasma science 1999-06, Vol.27 (3), p.688-700
• Main Authors: La Fontaine, B., Vidal, F., Comtois, D., Ching-Yuan Chien, Desparois, A., Johnston, T.W., Kieffer, J.-C., Mercure, H.P., Pepin, H., Rizk, F.A.M.
• Format: Article
• Language: English
• Subjects: Arcs, sparks, lightning; Breakdown; Computer simulation; Density; Electric breakdown; Electric discharges; Electric potential; Electricity; Electron density; Electrons; Exact sciences and technology; Fault location; Laser theory; Laser-plasma interactions; Lasers; Lightning; Mathematical models; Nitrogen; Numerical simulation; Optical pulses; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Plasma density; Plasma simulation; Voltage
• ISSN: 0093-3813; 1939-9375
• DOI: 10.1109/27.774673

In an ongoing program using ultrashort laser pulses to provoke discharges in air over considerable distances at electric fields below breakdown threshold, we have studied the conditions for the onset of streamers in such laser-produced plasmas, both experimentally and through numerical simulations. The results demonstrate the importance of the electron density and of its gradient on the generation of streamers. Also, a significant reduction of the breakdown voltage for a 30 cm plane-plane gap in air was observed with a laser pulse energy of 15 mJ. Finally, a direct comparison of laser-induced breakdown in air and in nitrogen shows the influence of electron attachment to oxygen on the discharge process.