Duration: 36 months
The ESA Voyage 2050 process identified multi-spacecraft plasma physics investigations as a target for the next phase of the science programme [1]. Two clear directions for these investigations were identified: cross scale coupling and electron energisation [2]. Cross scale coupling is addressed by NASA’s Helioswarm and ESA’s proposed M-Class Plasma Observatory missions, but electron energisation has no future mission study underway.
Electrons are nearly collisionless in space and so are energised by the action of electric fields generated by plasma motions. To observe and quantify this mechanism, electric field - electron interactions must be observed [3], requiring a novel kind of sensor that measures electron velocity distributions at high resolution and cadence and simultaneous electric field vectors to perform an analysis of the action of the electric field on the electrons [4]. These measurements must be made by multiple spacecraft at distances closer than 10km separation in space to distinguish the different electron kinetic processes that could be acting.
A future electron energisation mission could fit into an ESA F-class mission budget (e.g. past Debye and DREAM proposals) but requires high-TRL electron sensors. Existing high-TRL sensors create challenges for these missions as they are too large, create large amounts of data, and do not provide measurements of the combined electron and electric field interactions. A combined electron and electric field sensor with low mass and size to fit on small satellites would greatly improve future electron physics missions. Therefore, we propose to design and prototype a novel sensor to measure electron velocity distribution functions rapidly and at high resolution as well as simultaneous electric field measurements. These sensors will be small enough to enable the use of smallsats or large CubeSats and so enable a multi-spacecraft mission to be developed within the F-class budget for electron plasma physics.
