Imperial College London
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Dr Ravindra T. Desai

Faculty of Natural Sciences, Department of Physics

Academic Visitor
 
 
 
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Contact

 

ravindra.desai Website

 
 
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Location

 

Blackett LaboratorySouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Desai:2018:10.1002/2017GL076588,
author = {Desai, RT and Taylor, SA and Regoli, LH and Coates, AJ and Nordheim, TA and Cordiner, MA and Teolis, BD and Thomsen, MF and Johnson, RE and Jones, GH and Cowee, MM and Waite, JH},
doi = {10.1002/2017GL076588},
journal = {Geophysical Research Letters},
pages = {1704--1712},
title = {Cassini CAPS identification of pickup ion compositions at Rhea},
url = {http://dx.doi.org/10.1002/2017GL076588},
volume = {45},
year = {2018}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Saturn's largest icy moon, Rhea, hosts a tenuous surfacesputtered exosphere composed primarily of molecular oxygen and carbon dioxide. In this Letter, we examine Cassini Plasma Spectrometer velocity space distributions near Rhea and confirm that Cassini detected nongyrotropic fluxes of outflowing urn:x-wiley:grl:media:grl56939:grl56939-math-0001 during both the R1 and R1.5 encounters. Accounting for this nongyrotropy, we show that these possess comparable alongtrack densities of ∼2 × 10−3 cm−3. Negatively charged pickup ions, also detected during R1, are surprisingly shown as consistent with mass 26 ± 3 u which we suggest are carbonbased compounds, such as CN−, urn:x-wiley:grl:media:grl56939:grl56939-math-0002, urn:x-wiley:grl:media:grl56939:grl56939-math-0003, or HCO−, sputtered from carbonaceous material on the moon's surface. The negative ions are calculated to possess alongtrack densities of ∼5 × 10−4 cm−3 and are suggested to derive from exogenic compounds, a finding consistent with the existence of Rhea's dynamic CO2 exosphere and surprisingly low O2 sputtering yields. These pickup ions provide important context for understanding the exospheric and surface ice composition of Rhea and of other icy moons which exhibit similar characteristics.
AU  - Desai,RT
AU  - Taylor,SA
AU  - Regoli,LH
AU  - Coates,AJ
AU  - Nordheim,TA
AU  - Cordiner,MA
AU  - Teolis,BD
AU  - Thomsen,MF
AU  - Johnson,RE
AU  - Jones,GH
AU  - Cowee,MM
AU  - Waite,JH
DO  - 10.1002/2017GL076588
EP  - 1712
PY  - 2018///
SN  - 0094-8276
SP  - 1704
TI  - Cassini CAPS identification of pickup ion compositions at Rhea
T2  - Geophysical Research Letters
UR  - http://dx.doi.org/10.1002/2017GL076588
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000427564300001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - http://hdl.handle.net/10044/1/88626
VL  - 45
ER  -
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