Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.iki.rssi.ru/conf/2009elw/presentations/presentations_pdf/session7/vaisberg_ELW.pdf Дата изменения: Mon Mar 2 19:59:43 2009 Дата индексирования: Sun Apr 5 19:09:41 2009 Кодировка: Поисковые слова: emission

Investigation of surface and plasma environment of Europa and its interaction with Jovian magnetosphere
O.Vaisberg, G.Koinash IKI RAS, Russia J-J.Berthelier, D.Delcourt CETP, France F.Leblanc Serviece d'Aeronomy, France S.McKenna-Lawlor St. Patrick University, Ireland
International Workshop EUROPA LANDER, IKI, Moscow, 9-13 February, 2009


Interaction of satellites with Jovian magnetosphere

Auroral footprints can be seen in this image from Io (along the left hand limb), Ganymede (near the center), and Europa (just below and to the right of Ganymede's auroral footprint). These emissions, produced by electric currents generated by the satellites, flow along Jupiter's magnetic field, bouncing in and out of the upper atmosphere. This ultraviolet image of Jupiter was taken with the Hubble Space Telescope Imaging Spectrograph (STIS) on November 26, 1998 In this ultraviolet view.


Magnetospheric plasma near Europa


Energetic particles flux in the magnetosphere

Mauk et al., 2004

Radioti et al., 2005


Some important issues
Europa moves relative to magnetospheric magnetic field with velocity ~ 105 km/sec (subsonic velocity) Europa has induced magnetosphere and Alfven wings Europa has atmosphere (51014 cm-2) and ionosphere (~103 ­ 104 cm-3) Energetic particles hit Europa's surface that leads to sputtering rate of ~31027 molecules/sec Europa is an important source of neutrals particles (50kg of 2) and ionized particles in Jovian magnetosphere Mass and isotopic composition of these particles reflects the mass composition of Europa's surface


Scientific goals of experiment
Europa's surface and atmosphere
Atmospheric/ion composition and its losses to the magnetosphere Fluxes of accelerated ions and electrons near Europa and/or at its surface. Surface sputtering and implantation of energetic ions Mapping of surface composition

Jovian magnetosphere and its interaction with Europa
Ion composition of plasma and accelerated particles Europa's role in magnetospheric plasma population Magnetospheric plasma dynamics Electromagnetic interaction with Jupiter


Proposed experiment
Measurements of flux and velocity distribution of suprathermal and energetic ions and electrons, and mass/charge ion composition for investigation: - influence on Europa's surface - surface composition - Europa's atmospheric losses - composition of Europa and its atmosphere - Jovian magnetospheric plasma dynamics and the role of Europa in Jovian magnetosphere Onboard of lander, satellite of Europa or satellite of Jupiter


Electro-optics of electron spectrometer

Instantaneous sampling of velocity space, Emax/ Emin = 10 Cross-section of cylindrically-symmetric scheme


Electro-optics outlay of ion energymass-spectrometer

Instantaneous sampling of velocity space, Emax/ Emin = 10


Characteristics of instruments
· · · · · · · · · · · Two analyzers ­ ions and electrons Instant 2-dimensional measurements in velocity space Energy range : 10 eV ­ 50 keV Energy resolution: 10% Field of view: 50 3600 Instant energy range: E
max/Emin

= 10

Mass resolution of ion spectrometer, /: ~ 60 Total mass of 2 analyzers : 3.5 kg Status: development of laboratory prototype Heritage: SCA-1/Interball, FONEMA/Mars-96, DI/Phobos Soil PICAM/BepiColombo, DI/Phobos-soil Importance of simultaneous magnetic field measurements

Team: IKI, , Serviece d'Aeronomy St. Patrick University