eprintid: 1414089 rev_number: 33 eprint_status: archive userid: 608 dir: disk0/01/41/40/89 datestamp: 2013-11-08 20:10:18 lastmod: 2021-09-19 23:39:12 status_changed: 2013-11-08 20:10:18 type: article metadata_visibility: show item_issues_count: 0 creators_name: Coates, AJ creators_name: Wellbrock, A creators_name: Jones, GH creators_name: Waite, JH creators_name: Schippers, P creators_name: Thomsen, MF creators_name: Arridge, CS creators_name: Tokar, RL title: Photoelectrons in the Enceladus plume ispublished: pub divisions: UCL divisions: B04 divisions: C06 divisions: F63 keywords: Enceladus, photoelectrons, plume, ionosphere, Saturn, magnetosphere note: © 2013. American Geophysical Union. All Rights Reserved. Full text made available to UCL Discovery by kind permission of Wiley. abstract: 1] The plume of Enceladus is a remarkable plasma environment containing several charged particle species. These include cold magnetospheric electrons, negative and positive water clusters, charged nanograins, and “magnetospheric photoelectrons” produced from ionization of neutrals throughout the magnetosphere near Enceladus. Here we discuss observations of a population newly identified by the Cassini Plasma Spectrometer (CAPS) electron spectrometer instrument—photoelectrons produced in the plume ionosphere itself. These were found during the E19 encounter, in the energetic particle shadow where penetrating particles are absent. Throughout E19, CAPS was oriented away from the ram direction where the clusters and nanograins are observed during other encounters. Plume photoelectrons are also clearly observed during the E9 encounter and are also seen at all other Enceladus encounters where electron spectra are available. This new population, warmer than the ambient plasma population, is distinct from, but adds to, the magnetospheric photoelectrons. Here we discuss the observations and examine the implications, including the ionization source these electrons provide. date: 2013-08 official_url: http://dx.doi.org/10.1002/jgra.50495 vfaculties: VMPS oa_status: green full_text_type: pub primo: open primo_central: open_green verified: verified_manual elements_source: WoS-Lite elements_id: 914238 doi: 10.1002/jgra.50495 lyricists_name: Coates, Andrew lyricists_name: Jones, Geraint lyricists_name: Wellbrock, Anne lyricists_id: AJCOA20 lyricists_id: GHJON25 lyricists_id: AWELL44 full_text_status: public publication: JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS volume: 118 number: 8 pagerange: 5099 - 5108 issn: 2169-9380 citation: Coates, AJ; Wellbrock, A; Jones, GH; Waite, JH; Schippers, P; Thomsen, MF; Arridge, CS; Coates, AJ; Wellbrock, A; Jones, GH; Waite, JH; Schippers, P; Thomsen, MF; Arridge, CS; Tokar, RL; - view fewer <#> (2013) Photoelectrons in the Enceladus plume. JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS , 118 (8) 5099 - 5108. 10.1002/jgra.50495 <https://doi.org/10.1002/jgra.50495>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/1414089/1/jgra50495.pdf