Electron acoustic shock waves in a collisional plasma.

Area of Science:

• Plasma Physics
• Nonlinear Dynamics
• Space Physics

Background:

• Electron acoustic waves (EAW) are studied in collisional plasmas.
• Existing models often describe wave phenomena using the Korteweg-de Vries Burgers (KdVB) equation, which accounts for nonlinearity, dispersion, and dissipation.
• Dissipation typically arises from fluid viscosity in electron-ion plasmas.

Purpose of the Study:

• To investigate the nonlinear behavior of finite amplitude electron acoustic waves (EAW) in a collisional plasma.
• To explore the role of anomalous dissipation, beyond fluid viscosity, in wave dynamics.
• To determine if electron-ion collisions, in conjunction with plasma currents, can generate shock waves.

Main Methods:

• A fluid model is employed to describe the two-temperature electron species within a fixed ion background.
• Nonlinear analysis is performed to study wave propagation.
• Both analytical and numerical methods are utilized to examine the formation of shock waves.

Main Results:

• The study demonstrates that dissipation from electron-ion collisions, coupled with collective plasma phenomena like plasma current, introduces anomalous dissipation.
• This anomalous dissipation contributes a Burgers term to the governing equation, facilitating the generation of electron acoustic shock waves.
• Both analytical and numerical analyses confirm the formation of transient shock waves.

Conclusions:

• Anomalous dissipation mechanisms in collisional plasmas can lead to the formation of electron acoustic shock waves.
• The findings highlight the importance of considering collision-induced anomalous dissipation in understanding wave phenomena in space plasmas.
• The generated electron acoustic shock waves are transient, as indicated by both analytical and numerical results.