LAUSR

To determine (1) whether there is an ion‐composition (helium abundance) structure of the solar wind plasma at 1 AU that corresponds to the magnetic structure of the solar wind and to determine (2) whether the changes in the intensity of the electron heat flux correspond to magnetic boundaries, times when the alpha‐to‐proton number density ratio clearly changes and times when the outward‐electron‐strahl intensity clearly changes are collected. Then whether those times correspond to the locations of strong current sheets (directional discontinuities and flux‐tube walls) in the solar wind was statistically determined. In both cases (ion composition and strahl), the changes correspond to current‐sheet crossings. This indicates that flux‐tube walls statistically correspond to boundaries in the ion composition and the heat‐flux intensity. The implications for a fossil‐flux‐tube picture of the magnetic structure and an MHD (magnetohydrodynamic) turbulence picture of the structure are discussed.