AUTHOR=Borovsky Joseph E. , Halekas Jasper S. , Whittlesey Phyllis L. 

TITLE=The Electron Structure of the Solar Wind

JOURNAL=Frontiers in Astronomy and Space Sciences

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2021.690005

DOI=10.3389/fspas.2021.690005

ISSN=2296-987X

ABSTRACT=<p>Time-series measurements of the number density n<sub>core</sub> and temperature T<sub>core</sub> of the core-electron population of the solar wind are examined at 1 AU and at 0.13 AU using measurements from the WIND and Parker Solar Probe spacecraft, respectively. A statistical analysis of the n<sub>core</sub> and T<sub>core</sub> measurements at 1 AU finds that the core-electron spatial structure of the solar wind is related to the magnetic-flux-tube structure of the solar wind; this electron structure is characterized by jumps in the values of n<sub>core</sub> and T<sub>core</sub> when passing from one magnetic flux tube into the next. The same types of flux-tube jumps are seen for T<sub>core</sub> at 0.13 AU. Some models of the interplanetary electrical potential of the heliosphere predict that T<sub>core</sub> is a direct measure of the local electrical potential in the heliosphere. If so, then jumps seen in T<sub>core</sub> represent jumps in the electrical potential from flux tube to flux tube. This may imply that the interplanetary electrical potential (and its effect on the radial evolution away from the Sun of solar-wind ions and electrons) independently operates in each flux tube of the heliosphere.</p>