Two-stream instability with a growth rate insensitive to collisions in a dissipative plasma jet
The two-stream instability (Buneman instability) is traditionally derived as a collisionless instability with the presumption that collisions inhibit this instability. We show here via a combination of a collisional two-fluid model and associated experimental observations made in the Caltech plasma jet experiment, that in fact, a low frequency mode of the two-stream instability is indifferent to collisions. Despite the collision frequency greatly exceeding the growth rate of the instability, the instability can still cause an exponential growth of electron velocity and a rapid depletion of particle density. High collisionality nevertheless has an important effect as it enables the development of a double layer when the cross-section of the plasma jet is constricted by a kink-instigated Rayleigh-Taylor instability.
Supported by NSF Award 2105492 and by AFOSR Award FA9550-21-1-0379. Author Contributions. Yi Zhou: Formal analysis (equal); Investigation (equal); Methodology (equal); Software (lead); Validation (equal); Visualization (lead); Original draft preparation (lead); Review and editing (equal). Paul M. Bellan: Conceptualization (lead); Funding acquisition (lead); Formal analysis (equal); Investigation (equal); Methodology (equal); Project administration (lead); Supervision (lead); Validation (equal); Original draft preparation (supporting); Review and editing (equal). DATA AVAILABILITY. The data that support the findings of this study are available from the corresponding author upon reasonable request.
Accepted Version - 2304.06814.pdf