Journal article
Detection of dusty plasma near the E-ring of Saturn
Planetary and space science, Vol.57(14), pp.1795-1806
12/01/2009
DOI: 10.1016/j.pss.2009.03.011
Abstract
We present several independent in-situ measurements, which provide evidence that charged dust in the E-ring interacts collectively with the dense surrounding plasma disk of Saturn, i.e., form a system of dust-plasma interaction. The results are based on data sampled by the Radio and Plasma Wave Science (RPWS) investigation onboard Cassini, which allows for interferometry of plasma density inhomogeneities (δ
n/
n) with two antenna elements and a Langmuir probe sensor. The interferometer experiment detects two ion populations; one co-rotating with the planetary magnetic field and another moving with near Keplerian speed around Saturn. The full range of RPWS measurements indicates that the Keplerian population consists of colder ions (
T
i<few eV), which would interact with the electrical potential cavities associated with the few volts negatively charged E-ring water-rich dust grains. The presence of the charged dust inhibits
E×
B pick-up of freshly ionized particles by the rotating magnetic field of Saturn, since the local potential gradients near the dust grains are stronger than the large-scale co-rotation electric field. Even so, most ions are eventually energised to energies above the dust potentials of a few volts and become part of a hotter co-rotating ion population. The observed results have direct relevance to the interactions occurring in planet forming accretion disks around young stars, since the physical environment is similar.
Details
- Title: Subtitle
- Detection of dusty plasma near the E-ring of Saturn
- Creators
- J.-E. Wahlund - Swedish Institute of Space PhysicsM. André - Swedish Institute of Space PhysicsA.I.E. Eriksson - Swedish Institute of Space PhysicsM. Lundberg - Swedish Institute of Space PhysicsM.W. Morooka - Swedish Institute of Space PhysicsM. Shafiq - Swedish Institute of Space PhysicsT.F. Averkamp - University of IowaD.A. Gurnett - University of IowaG.B. Hospodarsky - University of IowaW.S. Kurth - University of IowaK.S. Jacobsen - University of OsloA. Pedersen - University of OsloW. Farrell - Goddard Space Flight CenterS. Ratynskaia - KTH Royal Institute of TechnologyN. Piskunov - Uppsala University
- Resource Type
- Journal article
- Publication Details
- Planetary and space science, Vol.57(14), pp.1795-1806
- Publisher
- Elsevier Ltd
- DOI
- 10.1016/j.pss.2009.03.011
- ISSN
- 0032-0633
- eISSN
- 1873-5088
- Language
- English
- Date published
- 12/01/2009
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984455658402771
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