Singly-ionized helium in the driver gas of an interplanetary shock wave
Abstract
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 4He+ ions travelling with the same speed as protons and α-particles. The occurrence of 4He+ 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.
- Publication:
-
Geophysical Research Letters
- Pub Date:
- March 1980
- DOI:
- 10.1029/GL007i003p00201
- Bibcode:
- 1980GeoRL...7..201S
- Keywords:
-
- Helium Plasma;
- Interplanetary Medium;
- Ionized Gases;
- Shock Wave Propagation;
- Cold Plasmas;
- Helios 1;
- Plasma Diagnostics;
- Rarefied Plasmas;
- Solar Protons;
- Particles and Fields-Interplanetary Space: Shock waves;
- Particles and Fields-Interplanetary Space: Solar wind plasma