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Observations of a high‐energy ion shock spike in interplanetary space
Author(s) -
Sarris E. T.,
Krimigis S. M.,
Armstrong T. P.
Publication year - 1976
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/gl003i003p00133
Subject(s) - physics , interplanetary spaceflight , interplanetary space , particle acceleration , shock (circulatory) , spacecraft , shock wave , acceleration , ion , interplanetary medium , solar energetic particles , nuclear physics , astrophysics , solar flare , energy (signal processing) , atomic physics , solar wind , plasma , coronal mass ejection , astronomy , mechanics , medicine , classical mechanics , quantum mechanics
The first observations of a high energy ion shock spike extending in energy to > 25 MeV for protons, > 4.3 MeV/nuc for alpha particles, and > 1.6 MeV/nuc for medium nuclei with Z ≥ 6 are reported. The measurements were obtained in the course of a solar particle event on September 15, 1974 by The Johns Hopkins University/Applied Physics Laboratory (JHU/APL) experiments on the IMP‐7 and IMP‐8 spacecraft. It is shown that the observations can be reasonably accounted for by intensive acceleration of charged particles at an "almost" perpendicular interplanetary shock wave. The data are inconsistent with a one‐step d.c.‐type acceleration process.