GENERATION OF A FAST IONIZATION WAVE IN A POSITIVE-COLUMN OF A NONSTEADY GAS-DISCHARGE

An experimental technique is developed for studying gas discharges by measuring the charge induced on the elements of the surrounding metal shield. The dispersion of waves excited in the positive column by a li near harmonic modulation of a steady-state low-pressure helium dischar ge is studied. Instantaneous potential distributions along the dischar ge channel are reconstructed for various modes of spatially nonuniform relaxation oscillations resulting from the onset of a convective inst ability in the ''plasma column-metal shield'' system. A solitary ioniz ation wave propagating with a velocity of 10(8) cm/s is observed.