The Plasma Observatory Ion and Mass Composition Analyzer [IMCA]

Plasma Observatory (PO) is the first multiscale mission tailored to study plasma energization and energy transport in the Earth's Magnetospheric System through simultaneous measurements at both ion and fluid scales. PO consists of seven identical small satellites (Sister SpaceCraft, SSC) that move on an equatorial elliptical orbit with an apogee of ~17 and a perigee of ~7 Earth radii in a two tetrahedra with a common vertex formation. The payload on board the SSCs give a full characterization of the plasma at the ion and fluid scales in the key science regions: bow shock, magnetosheath, magnetopause, transition region and magnetotail current sheet. In particular, resolving ion composition in 3D is needed since energization mechanisms work differently for different ion species (e.g. heavy ion effects on reconnection rate). The Ion Mass Composition Analyser (IMCA) will be able to provide the three-dimensional (3D) distribution functions for the near-Earth main ion species (H+, He++ and O+) with an energy range covering the thermal and suprathermal energies and an energy and angular resolution permitting to study the non-Maxwellian features in the ions distribution functions. IMCA will be embarked on at least four of the seven Sister SpaceCraft (one SSC of the inner tetrahedron and the three outer SSCs) in order to provide mass resolved 3D distribution at the fluid scales. Embarking IMCA on all the seven SSCs is currently under consideration. Here we will report on the IMCA objectives, design and consortium.