CO2-LASER PRODUCED CHANNELS FOR GUIDING LONG SPARKS IN AIR D. Koopman, J. Greig, R. Pechacek, A. Ali, I. Vitkovitsky et R. Fernsler J. Phys. Colloques, 40 C7 (1979) C7-419-C7-420 DOI: 10.1051/jphyscol:19797204