Ion Acoustic Wave Streamers Excited by a Resonantly Signal Biased Mesh Antenna in an Inhomogeneous Plasma

Electrostatic wave streamers are excited in an inhomogeneous plasma by a resonant disturbance generated by a mesh antenna biased with an oscillating signal. These low-frequency streamers are observed to move away from the mesh antenna through the under and overdense regions in the plasma. The average velocities of the downward and upward wave streamers are observed to be vd ≈ 2.51 × 10⁵ × cm/s and vu ≈ 1.63 × 10⁵ cm/s, respectively. Based on the order of the velocities of the wave streamers as that of the ion acoustic wave, we name them as ion acoustic wave streamers. Considering the flow of the ions in the plasma due to the density gradient, a theoretical model is developed that explains the nature and propagation characteristics of these experimentally observed streamers.