  This paper presents the detailed study of the controlled experimental
observation and characterization of Ion Acoustic soliton in the quiescent argon
plasma produced by filamentary discharge and confined in a multi-pole line cusp
magnetic field device named Multi-pole line Cusp Plasma Device (MPD). In this
system, the electrostatic fluctuations are found to be less than 1%, a
characteristic of quiescent plasma. Ion acoustic soliton has been excited in
MPD, and its propagation velocity and width of them are measured experimentally
and compared with the 1-D Korteweg-de Vries (KdV) equation. The interaction of
two counter-propagating solitons is also investigated to confirm propagation's
solitary nature further. After the successful characterization of ion-acoustic
soliton, the effect of varying the cusp magnetic field on the propagation of
ion-acoustic soliton has been studied. It is experimentally observed in MPD
that the pole cusp magnetic field value influences the excitation and
propagation of solitons. The soliton amplitude increases with the pole field up
to some value Bp~0.6kG, then decreases with the further increase in field
values. Meanwhile, the width of the soliton shows different behavior. The role
of primary electron confinement by cusp magnetic field geometry has been used
to explain the observed results.
