First results from the Fast Plasma Investigation on the MMS Mission

Abstract:

The Fast Plasma Investigation was developed to measure the differential directional flux of magnetospheric electrons and ions with unprecedented time resolution. The instrumentation is capable of resolving the kinetic plasma dynamics at spatial scales on the order of the electron and ion inertial lengths. This has been accomplished by deploying four dual 180^o top hat spectrometers for electrons and four for ions around the periphery of each MMS spacecraft. Using electrostatic field of view deflection, the eight spectrometers for each species together provide a 4pi sr field of view with 11.25 degree sample spacing. The radial phase space sampling is provided by swept electrostatic energy/charge selection over the range from 10 eV/q to 30,000 eV/q. This talk presents the first results from FPI with a focus on structures observed in the mid-tail region, including counter streaming electron populations and transient fast flows that are likely closely related to reconnection activity in the more distant down stream magnetotail. If possible, we will also present high time resolution electron and ion measurements available in the vicinity of the dusk-side flank magnetopause, possibly providing the first look at the plasma fine structure of the magnetopause and/or magnetopause boundary layer.