Meier, P. and Motschmann, U. and Schmidt, J. and Spahn, F. and Hill, T.W. and Dong, Y. and Jones, Geraint H. and Kriegel, H. (2015) Modeling the total dust production of enceladus from stochastic charge equilibrium and simulations. Planetary and Space Science , ISSN 0032-0633.
Abstract
Negatively and positively charged nano-sized ice grains were detected in the Enceladus plume by the Cassini Plasma Spectrometer (CAPS). However, no data for uncharged grains, and thus for the total amount of dust, are available. In this paper we estimate this population of uncharged grains based on a model of stochastic charging in thermodynamic equilibrium and on the assumption of quasi-neutrality in the plasma-dust system. This estimation is improved upon by combining simulations of the dust component of the plume and simulations for the plasma environment into one self-consistent model. Calibration of this model with CAPS data provides a total dust production rate of about 12 kg s−1, including larger dust grains up to a few microns in size. We find that the fraction of charged grains dominates over that of the uncharged grains. Moreover, our model reproduces densities of both negatively and positively charged nanograins measured by Cassini CAPS. In Enceladus' plume ion densities up to View the MathML source∼104cm−3 are required by the self-consistent model, resulting in an electron depletion of about 50% in the plasma, because electrons are attached to the negatively charged nanograins. These ion densities correspond to effective ionization rates of about View the MathML source10−7s−1, which are about two orders of magnitude higher than expected.
Metadata
Item Type: | Article |
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Keyword(s) / Subject(s): | Enceladus, Plume, Nanograin charge, CAPS |
School: | Birkbeck Faculties and Schools > Faculty of Science > School of Natural Sciences |
Depositing User: | Administrator |
Date Deposited: | 23 Oct 2015 09:52 |
Last Modified: | 02 Aug 2023 17:19 |
URI: | https://eprints.bbk.ac.uk/id/eprint/13174 |
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