Laboratory and Computer Simulations of Non-MHD Flute Instability Structuring the Plasma Clouds During their Artificial Releases at near-Earth Space

摘要

The fast non-MHD development of large-scale flutes at the boundary of plasma clouds expanding into magnetic field is a very common but still unclear phenomenon in a lot of geophysical (AMPTE Barium releases) and laboratory (laser plasma) experiments. To study its specific physics under conditions of the finite value of ion Larmor radius we had compared the data of AMPTE simulation at KI-1 facility with computer runs by electron Hall/MHD and Hybrid codes with taking into account magnetic field's diffusion relevant to the effect of anomalous electron collision frequency. It was found that the main experimentally observed features of flutes (their increment and non-linear stage) could be correctly described by these models. However, it requires this collision frequency of electrons to be proportional to their gyrofrequency, with values close to estimates derived earlier from KI-1 experiments through the phenomenology analysis of diamagnetic properties of exploding plasmas.