STRUCTURE OF A WEAKLY IONIZED GAS-DISCHARGE PLASMA

Analysis of the properties of weakly ionized plasmas suggests that str ong collective interactions exist in them in spite of the large distan ce between particles. Arguments supporting this view are presented. Fi rst among these is the existence of ''hidden'' mass, which is observed in experimental measurements of the aerodynamic drag forces. The hidd en mass causes an increase in the amplitude of sound waves in a plasma in comparison with an un-ionized gas at identical values of the gas p arameters. Analysis of the experimental results shows that gas-dischar ge plasmas contain previously unknown structural formations that are s pecific to a plasma and are of a standard type for each species of gas , independent of the pressure and temperature of the plasma. The conce ntration of particles making up the structure in the plasma of a gas d ischarge in air is 0.22X 10(17) cm(-3). (C) 1998 American Institute of Physics. [S1063-7850(98)01506-7]