1. 28.04.2005 | 9th MAG meeting, ESTEC, June 22-23, 2005 | page 1 Electron Spectrometer On Swarm

2. 28.04.2005 | 9th MAG meeting, ESTEC, June 22-23, 2005 | page 2 On the Advantage of a Particle Experiment B is integrated property: sum of contributions from all electric currents j in the Earth’s core, ionosphere, but also on the spacecraft... In-situ measurement of electric field E with EFI, and of local current density j with curl-B technique These currents have only minor direct effect on estimation of core and crustal field since they are (mathematically) orthogonal to a potential field But they have a significant indirect impact, since they feed ionospheric currents, J (ionospheric currents are internal for Swarm, and may therefore disturb internal field models) Missing link: ionospheric conductivity  produced by electron precipitation (at polar latitudes) Particle experiment provides information on ionospheric conductivity 

3. 28.04.2005 | 9th MAG meeting, ESTEC, June 22-23, 2005 | page 3 Concept Electron Spectrometer

4. 28.04.2005 | 9th MAG meeting, ESTEC, June 22-23, 2005 | page 4 Block Diagram

5. 28.04.2005 | 9th MAG meeting, ESTEC, June 22-23, 2005 | page 5 Resource Requirements and Specifications Mass1 kg Power3 w Size0.1 x 0.2 x 0.1 m Field-of-view210º x 10º, 16 Sectors 64 Energy Levels Energy Range 10 eV – 30 keV Energy ResolutionΔE/E = <8% Field-of-view in orbit plane (B-field plane) Data Rate2 kb/sec compressed 90% Purge required Cost Estimate2 M€ for STM-EM-3 FM-QM/FS ConsortiaDNSC – IRF - RIT