MIMI: Magnetospheric IMaging Instrument

Steven Kapturowski

What is MIMI?

s  Neutral and charged particle detection system s  1st Instrument designed to image planetary

magnetospheres s  Global Imaging and in-situ measurement s  Determine magnetospheric structure & dynamics

The Saturn System

s  Rings, moons, magnetosphere, and atmosphere are tightly coupled

s  Numerous plasma sources s  Weak radiation belts s  Buildup of Magnetic Field Lines in front

of Moons

A bit about Magnetospheres…

s  Shearing of field lines ßà current sheets

s  Ions tied to field lines; “frozen-in”

The Big Questions

s  Voyager I established complicated magnetospheric system, but how does it compare to Jupiter?

s  How important magnetosphere-moon interaction?

s  Are substorms universal? s  Plasma sources?

Scientific Objectives s  Determine global configuration and dynamics of magnetospheric

plasmas s  Determine plasma sources s  Search for and characterize magnetospheric substorms. s  Determine magnetosphere-satellite-ring interactions and neutral

hydrogen, nitrogen, and water product cloud formation s  Investigate effect of plasma / radiation bombardment on satellite

surfaces, rings, and atmospheres s  Characterize Titan's interaction with Saturn's magnetosphere

and solar wind s  Assess the Cosmic Ray Albedo (CRAND) source of energetic

charged particles in the magnetosphere. s  Characterize absorption of energetic ions and electrons by

satellites and rings s  Study magnetosphere-ionosphere coupling

Traceability (outside of a matrix)

s  Charge exchange neutrals à Plasma images s  Composition & distribution à Sources s  Neutral ion mapping à Neutral cloud formation s  Equatorial Orbits à Satellite-plasma interactions s  Inclined Orbits à Ring images s  High Energy (1.6-160 MeV) ions à CRAND source

Trajectory Design

s  Earth swingby used for calibration s  Swingby through Jovian current sheet s  Close encounters with Saturn’s moons s  Titan used for gravity assists

Instrument Architecture CHEMS

LEMMS

INCA

DPU

Charge Energy Mass Spectrometer

Ion Neutral Camera

Low-E Magnetospheric Measurements System

s  3 different detectors serviced by same electronics

s  CHEMS: measures charge & composition of ~3-220 keV/e ions

s  LEMMS: particle spectrometer measures 3D distribution of ion/electron fluxes

s  INCA: measures ENAs and distribution, E-spectra, & crude composition of ~7-3000 keV/nuc ions

MIMI Specs s  Mass: 16.00 kg s  Operating Power: 14.00 W s  Data Rate: 7.00 kilobits/s

Energy

Cha

rge

+

-

LEMMS

INCA

CHEMS

LEMMS

INCA

Results s  Radiation belt discovered within Saturn’s rings s  Stability of radiation belts within Tethys orbit s  Charged water products from icy moons s  Enceladus, Dione, and Titan are strong sources s  Asymmetric Halo of ENAs around Titan

Sources s  http://lasp.colorado.edu/%7Ehoranyi/graduate_seminar/

Magnetosphere_Imaging_MIMI.pdf s  http://www.universetoday.com/40065/temporary-radiation-belt-discovered-

at-saturn/

s  http://www.springerlink.com/content/mm5187372h6l7123/ s  http://mapsview.engin.umich.edu/data_descriptions/MIMI_instrument.php

Questions?