Felici, M;
Arridge, CS;
Wilson, RJ;
Coates, AJ;
Thomsen, M;
Reisenfeld, D;
(2018)
Survey of Thermal Plasma Composition in Saturn's Magnetosphere Using Time-of-Flight Data From Cassini/CAPS.
Journal of Geophysical Research: Space Physics
, 123
(8)
pp. 6494-6513.
10.1029/2017JA025085.
Preview |
Text
Felici_et_al-2018-Journal_of_Geophysical_Research%3A_Space_Physics.pdf - Published Version Download (2MB) | Preview |
Abstract
The Cassini spacecraft orbited Saturn from 2004 to 2017, and in 2006 it started exploring the deep magnetotail, reaching distances of about 68 RS (where RS is the equatorial radius of Saturn). Since Cassini covered a broad area of Saturn's magnetosphere, this raises the question of what is the typical and atypical plasma composition in different regions of Saturn's environment. In this paper, we present a survey of the bulk plasma composition using time‐of‐flight data from the Plasma Spectrometer/Ion Mass Spectrometer instrument on Cassini, from 2004 through 2012. This is the most comprehensive study ever made of relative abundances of thermal plasma at Saturn, maximizing the use of Cassini's orbital coverage in Saturn's magnetosphere during those years, and, therefore, the sensitivity to seasonal or natural variability of the system. We studied the ratio of counts between ions with E/q≃1.19–21,300 eV/q and mass per charge equal to 2 (either H+2 or He++) and ionized hydrogen ([(m/q = 2)]/[H+]), and a mixture of ions (H2O+, H3O+, OH+, and O+), known as the water group (W+) and ionized hydrogen ([W+]/[H+]). We present the data as a function of position in the magnetosphere, radial distance and local time, and distance from the planet and longitude with respect to the moons Enceladus, Dione, Rhea, and Titan. We found that the plasma composition in Saturn's magnetosphere presents significant local time asymmetries and variability.
| Type: | Article |
|---|---|
| Title: | Survey of Thermal Plasma Composition in Saturn's Magnetosphere Using Time-of-Flight Data From Cassini/CAPS |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1029/2017JA025085 |
| Publisher version: | https://doi.org/10.1029/2017JA025085 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10056561 |
Archive Staff Only
 |
View Item |
