iEPC - Electrostatic ion/electron analyzer

The purpose of iEPC is to provide measurements of the 3D distribution function of thermal and supra-thermal ions and electrons (10 eV – 25 keV) in the key science regions targeted by PO.

In order to understand how ion scale energization processes are governed by multi-scale phenomena, these measurements shall be possible with a temporal resolution of 250 ms in PO smaller tetrahedron, with 20% energy resolution, and with 22.5° angle resolution, and at lower time resolution at fluid scale.

The iEPC design only requires a set of 2 plasma cameras to fulfill PO measurement requirements, each camera performing both ion and electron measurements at high cadence due to their very high sensitivity (i.e. geometric factor).

The iEPC is an innovative electrostatic analyser which is based on the ”donut” analyzer concept. It will provide instantaneous sky coverage of magnetospheric plasmas thanks to its Donut Electrostatic Optics (DEO). Energy range is 10 eV to 25 keV with an energy resolution of 11%. The iEPC geometric factor of 3.7·10−4 cm2·sr·eV/eV per pixel ensures very high counting statistics at the required 250 ms time resolution.

The iEPC consortium is led by LPP (France), with contributions from IRAP/LAB (France) and MSSL (United Kingdom). The iEPC instrument uses a combination of high-heritage components, whose subsystems are flying on Solar Orbiter and JUICE.