The Electric Field and Waves (EFW) Instrument on the NASA Radiation Belt Storm Probes (RBSP) Mission: Investigating the Physical Mechanisms of Energetic Particle Acceleration in the Inner Magnetosphere

Measurement of the DC and low-frequency electric field in the inner magnetosphere is a crucial element of any attempt to determine the physical mechanisms of energization, transport, and loss of energetic particles in the terrestrial radiation belts. Each of the two satellites in the NASA Radiation Belt Storm Probes (RBSP) mission will be equipped with a three-axis E-field instrument, the Electric Fields and Waves (EFW) instrument (J. R. Wygant, PI). This instrument provides direct waveform, spectral, and interferometric measurements of DC and low-frequency electric fields and fluctuations, as well as supports coordinated measurements of waveform and spectral data of both the electric and magnetic fields through collaboration with the Electric and Magnetic Field Instrument Suite with Integrated Science (EMFISIS) instrument. The requirements and capabilities of the EFW instrument will be described and compared against previous suites of field instruments flow in the inner magnetosphere, and the application of those measurements to salient unresolved aspects of energetic particle dynamics in the inner magnetosphere and terrestrial radiation belts will be explored.