transmis par Matthieu Berthomier (LPP)
Titre : Modeling, development, and test of a 3D-printed plasma camera for in-situ measurements in space
Lieu: Amphi Becquerel, Ecole Polytechnique
Visio: https://cnrs.zoom.us/j/94006980904?pwd=LD4CXeKU3RLZ8UnF4BxhxICJlzfOIb.1
Meeting : 940 0698 0904 / n42B1H
Résumé:
Space plasma dynamics are governed by multi-scale phenomena. However, the reference instruments used to measure the energy distribution of charged particles have a limited field of view. Adding electrostatic deflection systems overcomes this limitation but has the disadvantage of making these instruments heavier, slowing their measurement cadence, and ultimately reducing their performance. It is therefore crucial to develop compact and high-performance instruments suited for satellite constellations. This thesis focuses on the development of instruments based on an innovative toroidal topology that provides an instantaneous hemispherical field of view, effectively turning them into true plasma cameras.
The development of a parametric tool enabled the numerical characterization of tens of instruments with various sizes and angular resolutions to address different scientific needs. A compact model designed for space weather monitoring was developed using innovative 3D printing and selective metallization processes. This plasma camera features 64 viewing directions, an energy range up to 22 keV, and a dual ion/electron detection capability enabled by a carbon-based conversion layer. Weighing 1.8 kg with a diameter of 19 cm, this instrument is well suited for nanosatellites.
The principle of the conversion system was validated under helium and nitrogen ion beams. The electrostatic optics was characterized under an electron beam across a wide range of energies and angles, with results closely matching simulations, thereby increasing confidence in numerical modelling. Following this thesis and with the support of CNES, a fully operational model of this plasma camera will be developed, aiming in-orbit demonstration in the coming years.
Jury:
Dr. Iannis Dandouras, IRAP – Rapporteur
Dr. Jim Raines, University of Michigan – Rapporteur
Dr. Vincent Maget, ONERA – Examinateur
Pr. Pascal Chabert, Ecole Polytechnique – Examinateur
Dr. Pierre Henri, OCA Lagrance/LPC2E – Examinateur
Dr. Matthieu Berthomier, LPP – Directeur de Thèse
Dr. Carla Costa, CNES – Invitée