An analysis of electron Landau damping as a turbulent dissipation mechanism in the terrestrial magnetosheath

As our species becomes further reliant on technology and in the near future becomes a multi-planetary species, the knowledge of our solar system becomes increasingly important. The space between the Sun and planets (interplanetary space) is filled with a charged gas (plasma) that contains an embedded magnetic field. This plasma originates from the Sun and is called the solar wind. As the solar wind expands outward in all directions, it interacts with the planets, comets, and man-made satellites. One such interaction of the solar wind is with the Earth's magnetic bubble (magnetosphere). When the solar wind comes into contact with the magnetosphere, a relatively thin barrier is formed (magnetosheath). In the magnetosheath, the solar wind is slowed down tremendously and deflected around the Earth, thus the magnetosheath is denser and hotter than the pristine solar wind. There is a lot of energy stored in the turbulent flow of the solar wind, and in the magnetosheath some of the turbulent energy is converted to plasma particle energy.

This dissertation addresses how the turbulent energy from the solar wind is ultimately handed to the particles. One of the mechanisms that mediates this transfer of energy is called Landau damping, and in this work we identify signatures of Landau damping in velocity-space. We characterize how much of turbulent energy exists in the low frequency fluctuations of the plasma particles and the magnetic field, and how much of that energy is deposited into the electrons. The directionality of the wave energy and its effect on the signature of Landau damping is also established.