Plasma Seismology: Fully Exploiting Velocity Distributions to Recover Spatial Electric Field Structure

This award supports development of a novel space plasma measurement methodology called plasma seismology that uses measurements of the velocity distribution function of particles at a single point in space to reconstruct the variation of the electric field over an extended spatial region. In space plasmas, the electric field plays a key role in collisionless wave-particle interactions that govern the acceleration of particles to high energy. Such a new capability may provide valuable information needed to understand the dynamics of space phenomena with significant societal impacts, such as severe space weather events that can impact our communication and navigation satellites as well as potentially cause severe damage to the electrical power grid. Further, by determining the electric field over an extended spatial range with fewer spacecraft, this innovative technique holds the promise to reduce the cost of future spacecraft missions. This project will also support the education and training of a graduate student in both the numerical and experimental investigation of kinetic plasma physics. This project will first validate the plasma seismology technique for electrostatic dynamics to determine the spatial variation of the electric field through single-point, time-series measurements of the electron velocity distribution function using kinetic electrostatic simulations. Second, the procedure for plasma seismology in electromagnetic plasmas relevant to space environments will be developed and validated using single-point, time-series measurements of the electron velocity distribution from kinetic electromagnetic simulations of plasma turbulence. Finally, the feasibility of the plasma seismology implementation will be confirmed by determining the spatial variation of the parallel electric field in laboratory experiments. Close coordination of the analytical, numerical, and experimental tasks will enable the development of the innovative technique of plasma seismology to be used as a new tool to probe the electric fields in laboratory and space plasmas over a greater spatial extent than currently possible with existing technological capabilities. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.