Exploring Energy Transfer from the Bell Instability using Simulations and Field-Particle Correlation Analysis

Streaming instabilities are a potentially significant mechanism for transferring energy across different length scales in collisionless turbulent plasma systems. The non-resonant streaming, or Bell, instability can drive non-linear magnetic fluctuations with MHD scale wavelengths and couples the long length scales associated with non-thermal particles to the kinetic scales of the thermal population. To understand the multi-scale energization process, we perform kinetic hybrid particle-in-cell simulations of the Bell instability and analyze both the linear and non-linear growth phase using kinetic dissipation diagnostics including field particle correlations and Pi-D. In the linear phase, the thermal protons are energized through ion cyclotron damping while a segment of the non-thermal population is scattered through gyro-resonant interactions with the instability. In the non-linear phase, the thermal population is heated considerably and through non-compressional channels. These results have consequences for our understanding of the Bell instability and its role in cross scale energization/dissipation in collisionless plasma systems including the solar wind in the vicinity of CMEs and Earths Bow shock and magnetosheath.