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Singly‐ionized helium in the driver gas of an interplanetary shock wave
Author(s) -
Schwenn Rainer,
Rosenbauer Helmut,
Mühlhäuser KarlHeinz
Publication year - 1980
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/gl007i003p00201
Subject(s) - physics , plasma , atomic physics , solar wind , ion , helium , proton , interplanetary spaceflight , solar prominence , shock wave , ionization , spectral line , shock (circulatory) , astrophysics , astronomy , nuclear physics , mechanics , magnetic field , medicine , quantum mechanics
The interplanetary shock wave observed on Jan. 29, 1977 by the HELIOS‐1 plasma instruments shows an unusual feature: In the cold tenuous piston plasma following this shock, there appears a third peak in the energy per charge (E/q) spectra, in addition to the normal proton and α‐particle peaks. The peak is located at E/q = 4 and persists for about 14 hours, with slowly varying intensities. Independent simultaneous measurement of these particles’ charge yields a value of ≈ 1. These ions are thought to be 4 He + ions travelling with the same speed as protons and α‐particles. The occurrence of 4 He + indicates the possibility that during eruptive prominences or other solar transients “cold” chromosperic plasma might escape from the sun without undergoing the normal coronal heating process.