Authors: Phyllis Whittlesey (UCB/SSL), Justin Kasper (BWXT), Davin Larson(UCB/SSL), Michael Stevens (SAO), Anthony Case (SAO), Orlando Romeo(UCB/SSL), Jasper Halekas (U Iowa), Ali Rahmati (UCB/SSL)

The SWEAP/SPAN-Electron sensors on Parker Solar Probe (PSP) measure the 3D distributions of solar wind electrons, including total flux, velocity, and temperature, in the inner heliosphere. Strahl electrons, which are the high energy, beam-like component of the solar wind electron population, flow outward from the sun along magnetic field lines, and thus serve as excellent tracers of magnetic topology and magnetic solar connectivity. Comparing strahl electron pitch angle distributions (PADs) to PSP/FIELDS magnetic field data, we find the strahl electrons reverse direction and briefly flow sunward during the numerous intervals in PSP’s encounters where the sense of the magnetic field briefly reverses. The strahl PADs, in agreement with measurements from the Solar Probe Cup (SPC) and SPAN-Ion instruments, therefore indicate that these intervals, termed “switchbacks”, are likely not related to large-scale solar magnetic field polarity reversals, but are kinks and reversals in the solar magnetic field originating elsewhere and propagating outward from the sun. This work details the strahl electron population during rapid magnetic field rotation intervals compared to non-switchback periods, in particular during those periods where the fastest SPAN-E electron PAD data are available. Furthermore, strahl flow vector deviations from the local magnetic field are quantified on the fastest electron PAD timescales.