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Energetic (>100 keV) O + ions in the plasma sheet
Author(s) -
Ipavich F. M.,
Galvin A. B.,
Gloeckler G.,
Hovestadt D.,
Klecker B.,
Scholer M.
Publication year - 1984
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl011i005p00504
Subject(s) - substorm , plasma sheet , magnetosphere , physics , ion , plasma , atomic physics , van allen probes , van allen radiation belt , nuclear physics , quantum mechanics
We present the first measurements of very energetic (112 ‐ 157 keV) O + ions in the earth's magnetosphere. The observations were made with the UMd/MPE ULECA sensor on ISEE‐1 on 5 March 1981 at geocentric distances ∼20 R E in the earth's magnetotail. During this time period an Energetic Storm Particle event was observed by our nearly identical sensor on the ISEE‐3 spacecraft, located ∼250 R E upstream of the earth's magnetosphere. The ISEE‐1 sensor observed a similar temporal profile except for several sharp intensity enhancements, corresponding to substorm recoveries during which the plasma sheet engulfed the spacecraft. During these plasma sheet encounters we observe O + /H + abundance ratios, at ∼130 keV, as large as 0.35. In between plasma sheet encounters the O + /H + ratio at this energy is consistent with zero.