WIDE SOLITONS IN AN ION-BEAM-PLASMA SYSTEM

Solitons are experimentally found in a double plasma device when an io n beam is present with beam velocity vb in the range 1 less than or eq ual to nu(b)/c(s) less than or equal to 2.2, where c(s) is the ion aco ustic velocity. These one dimensional solitons have an unusually large width (parallel to the direction of propagation) W approximate to 14 lambda(D)(delta n/n)(-1/2), where lambda(D) is the Debye length and de lta n/n is the maximum normalized density fluctuation. The amplitude, width, and velocity characteristics of the solitons are found to be in good agreement with the soliton solution to the Korteweg-de Vries equ ation in an ion-beam-plasma system.