19.04. 2012

Solar Wind – Time Development of Waves

The solar wind is a high flow of plasma from the Sun which fills the solar system. As the solar wind flows away from the Sun it expands, and this expansion changes the particle distribution function within the plasma. This can only happen because the plasma is very low density and very high temperature so that it is collisionless, which means that the particle distribution functions are not forced to be stable Maxwellian distributions as in a normal gas.
The distortion of the particle distribution drives an instability which produces waves. This process is entirely due to collisionless kinetics of the space plasma system. The image shows the time development (from left to right) of waves driven by the electron fire hose instability in an expanding plasma (Camporeale and Burgess, ApJ 710:1848–1856, 2010). These waves are believed to be responsible for constraining the electron particle distribution function.

Credit: Enrico Camporeale and David Burgess
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